Sickle Cell Disease

Also known as Sickle Cell Anemia, Hemoglobin S or SS disease, Sickling disorder due to hemoglobin S
Sickle cell disease is a group of inherited red blood cell disorders. People who have sickle cell disease have an abnormal protein in their red blood cells. In the United States, most people who have sickle cell disease are of African ancestry, but the condition is also common in people with a Hispanic background. Because the disease runs in families, couples planning to have children can have genetic testing.

Early signs and symptoms of sickle cell disease include swelling of the hands and feet; symptoms of anemia, including fatigue, or extreme tiredness; and jaundice. Over time, sickle cell disease can lead to complications such as infections, delayed growth, and episodes of pain, called pain crises. Most children who have sickle cell disease are pain-free between crises, but adolescents and adults may also suffer with chronic, ongoing pain. Over a lifetime, sickle cell disease can harm a patient’s spleen, brain, eyes, lungs, liver, heart, kidneys, penis, joints, bones, or skin.

A blood and bone marrow transplant is currently the only cure for sickle cell disease, and only a small number of people who have sickle disease are able to have the transplant. There are effective treatments that can reduce symptoms and prolong life. Early diagnosis and regular medical care to prevent complications also contribute to improved well-being. Sickle cell disease is a lifelong illness. The severity of the disease varies widely from person to person.

Explore this Health Topic to learn more about sickle cell disease, our role in research and clinical trials to improve health, and where to find more information.

Types - Sickle Cell Disease

People who have sickle cell disease have abnormal hemoglobin, called hemoglobin S or sickle hemoglobin, in their red blood cells. Hemoglobin is a protein in red blood cells that carries oxygen throughout the body. People who have sickle cell disease inherit two abnormal hemoglobin genes, one from each parent.

The types of sickle cell disease include the following:

  • Hemoglobin Sβ0 thalassemia
  • Hemoglobin Sβ+ thalassemia
  • Hemoglobin SC
  • Hemoglobin SD
  • Hemoglobin SE
  • Hemoglobin SS

In all types of sickle cell disease, at least one of the two abnormal genes causes a person’s body to make hemoglobin S. When a person has two hemoglobin S genes (hemoglobin SS), the disease is called sickle cell anemia. This is the most common and often most severe type of sickle cell disease. Hemoglobin SC disease and hemoglobin Sβ thalassemia are two other common types of sickle cell disease. Hemoglobin SD and hemoglobin SE are much less common.

Causes - Sickle Cell Disease

Abnormal hemoglobin, called hemoglobin S, causes sickle cell disease.

Hemoglobin S gene
- Sickle Cell Disease

Sickle cell disease is an inherited disease caused by defects, called mutations, in the beta globin gene that helps make hemoglobin. Normally, hemoglobin in red blood cells takes up oxygen in the lungs and carries it through the arteries to all the cells in the tissues of the body. Red blood cells that contain normal hemoglobin are disc-shaped and flexible so that they can move easily through large and small blood vessels to deliver oxygen.

Sickle hemoglobin is not like normal hemoglobin. The mutations in the gene cause a problem when oxygen levels in the blood are lower, which occurs once the hemoglobin has delivered oxygen to the cells in the body’s tissues. With less oxygen, the abnormal hemoglobin S gene can cause rigid, nonliquid protein strands to form within the red blood cell. These rigid strands can change the shape of the cell, causing the sickled red blood cell that gives the disease its name.

Sickle-shaped cells are not flexible and can stick to vessel walls, causing a blockage that slows or stops the flow of blood. When this happens, oxygen is unable to reach nearby tissues. The lack of oxygen in tissue can cause attacks of sudden severe pain, called pain crises. These pain attacks can occur without warning, and a person who has them often needs to go to the hospital for effective treatment.

Because sickle cells cannot change shape easily, they tend to burst apart. Normal red blood cells live about 90 to 120 days, but sickle cells last only 10 to 20 days. The body is always making new red blood cells to replace the old cells. However, in sickle cell disease, the body may have trouble keeping up with how fast the cells are being destroyed. Because of this, the number of red blood cells is usually lower than normal. This condition, called anemia, can cause a person to have less energy.

Normal Red Cells and Sickle Red Cells.
Normal red cells and sickle red cells. Figure A shows normal red blood cells flowing freely in a blood vessel. The inset image shows a cross-section of a normal red blood cell with normal hemoglobin. Figure B shows abnormal, sickled red blood cells blocking blood flow in a blood vessel. The inset image shows a cross-section of a sickle cell with abnormal (sickle) hemoglobin forming abnormal stiff rods.

 

How is the hemoglobin S gene inherited?
- Sickle Cell Disease

When the hemoglobin S gene is inherited from only one parent, and a normal hemoglobin gene—hemoglobin A—is inherited from the other, that person will have sickle cell trait. People who have sickle cell trait are generally healthy.

Only rarely do people who have sickle cell trait have complications similar to those seen in people who have sickle cell disease. But people who have sickle cell trait are carriers of a defective hemoglobin S gene, so they can pass it on when they have a child.

If the child’s other parent also has sickle cell trait or another abnormal hemoglobin gene, such as beta-thalassemia, hemoglobin C, hemoglobin D, or hemoglobin E, that child has a chance of having sickle cell disease.

 Image showing how sickle cell disease is inherited.
Inheritance pattern for sickle cell disease. The image shows how hemoglobin S genes are inherited. A person inherits two hemoglobin genes—one from each parent. A normal hemoglobin A gene will make normal hemoglobin. A hemoglobin S gene will make abnormal hemoglobin.

In the image above, each parent has one normal hemoglobin A gene and one hemoglobin S gene, which means each of their children has:

  • A 25 percent chance of inheriting two normal hemoglobin A genes. In this case, the child does not have sickle cell trait or disease.
  • A 50 percent chance of inheriting one normal hemoglobin A gene and one hemoglobin S gene. This child has sickle cell trait.
  • A 25 percent chance of inheriting two hemoglobin S genes. This child has sickle cell disease.

It is important to keep in mind that each time this couple has a child, the chances of that child having sickle cell disease remain the same. In other words, if the firstborn child has sickle cell disease, there is still a 25 percent chance that the second child will also have the disease. Both boys and girls can inherit sickle cell trait, sickle cell disease, or normal hemoglobin.

If a person wants to know whether he or she carries a sickle hemoglobin gene, a doctor can order a blood test to find out.

Risk Factors - Sickle Cell Disease

In the United States, most people who have sickle cell disease are of African ancestry or identify themselves as black.

  • About 1 in 13 black or African American babies is born with sickle cell trait.
  • About 1 in every 365 black or African American babies is born with sickle cell disease.

There are also many people who have sickle cell disease who come from Hispanic, southern European, Middle Eastern, or Asian Indian backgrounds.

About 100,000 Americans have sickle cell disease.

Screening and Prevention - Sickle Cell Disease

People who do not know whether they carry an abnormal hemoglobin gene can ask their doctor to have their blood tested.

Couples who are planning to have children and know that they are at risk of having a child with sickle cell disease may want to meet with a genetic counselor. A genetic counselor can answer questions about the risk and explain the choices that are available.

Look for
- Sickle Cell Disease

  • Diagnosis will discuss tests and procedures that your doctor may use to diagnose sickle cell disease for you or your baby.
  • Living With will discuss what your doctor may recommend to manage your complications.
  • Research for Your Health will discuss how we are using current research and advancing research to treat and cure sickle cell disease.
  • Participate in NHLBI Clinical Trials will discuss our open and enrolling clinical studies that are investigating treatment and approaches for sickle cell disease.

Signs, Symptoms, and Complications - Sickle Cell Disease

Sickle cell disease is a lifelong illness. The severity of the disease varies widely from person to person. People with sickle cell disease can experience both acute and chronic signs, symptoms, and complications.

Early signs and symptoms
- Sickle Cell Disease

If a person has sickle cell disease, it is present at birth. But most newborns do not have any problems from the disease until they are about 5 or 6 months of age. Every state in the United States, the District of Columbia, and the U.S. territories require that all newborn babies receive screening for sickle cell disease. When a child has sickle cell disease, the parents are notified before the child has symptoms.

Some children who have sickle cell disease will start to have problems early on, and some later. Early symptoms of sickle cell disease may include:

  • A yellowish color of the skin, known as jaundice, or whites of the eyes, known as icterus, that occurs when a large number of red cells undergo hemolysis
  • Fatigue or fussiness from anemia
  • Painful swelling of the hands and feet, known as dactylitis

The signs and symptoms of sickle cell disease will vary from person to person and can change over time. Most of the signs and symptoms of sickle cell disease are related to complications of the disease.

Complications
- Sickle Cell Disease

Complications of sickle cell disease include:

  • Acute chest syndrome. Sickling in blood vessels of the lungs can deprive a person’s lungs of oxygen. When this happens, areas of lung tissue are damaged and cannot exchange oxygen properly. This condition is known as acute chest syndrome. In acute chest syndrome, at least one segment of the lung is damaged. This condition is very serious and should be treated right away at a hospital. Acute chest syndrome often starts a few days after a painful crisis begins. A lung infection may accompany acute chest syndrome.
  • Acute pain crisis, also known as sickle cell or vaso-occlusive crisis. Acute pain crisis can occur without warning when sickle cells block blood flow and decrease oxygen delivery. People describe this pain as sharp, intense, stabbing, or throbbing. Severe crises can be even more uncomfortable than postsurgical pain or childbirth. Pain can strike almost anywhere in the body and in more than one spot at a time. Common areas affected by pain include the abdomen, chest, lower back, or arms and legs. A crisis can be brought on by high altitudes, dehydration, illness, stress, or temperature changes. Often a person does not know what triggers, or causes, the crisis.
  • Brain complications, such as a clinical or silent stroke. In sickle cell disease, a clinical stroke means that a person shows signs of a stroke. However, children and adults who have hemoglobin SS and hemoglobin Sβ0 thalassemia often have signs of silent brain injury, also called silent stroke. Silent brain injury is damage to the brain without showing outward signs of stroke. This injury is common and can be detected on magnetic resonance imaging (MRI) scans. Silent brain injury can lead to difficulty in learning, making decisions, or holding down a job.
  • Chronic pain. Many adolescents and adults who have sickle cell disease experience chronic pain. This kind of pain has been hard for people to describe, but it is usually different from crisis pain or the pain that results from organ damage.
  • Delayed growth and puberty. Children who have sickle cell disease may grow and develop more slowly than their peers because of anemia. They will reach full sexual maturity, but this may be delayed.
  • Eye problems. Sickle cell disease can injure blood vessels in the eye. The most common site of damage is the retina, where blood vessels can overgrow, get blocked, or bleed. The retina is the light-sensitive layer of tissue that lines the inside of the eye and sends visual messages through the optic nerve to the brain. Detachment of the retina can occur. When the retina detaches, it is lifted or pulled from its normal position. These problems can cause visual impairment or loss.
  • Gallstones. When red cells undergo hemolysis, they release hemoglobin. Hemoglobin gets broken down into a substance called bilirubin. Bilirubin can form stones that get stuck in the gallbladder. The gallbladder is a small sac-shaped organ beneath the liver that helps with digestion. Gallstones are a common problem in sickle cell disease.
  • Heart problems, including ischemic heart disease and pulmonary hypertension. People who have sickle cell disease who have received frequent blood transfusions may also have heart damage from iron overload.
  • Infections. The spleen is important for protection against certain kinds of infections. People who have sickle cell disease and damaged spleens are at risk for certain kinds of infections, including chlamydia, haemophilus influenzae type B, salmonella, and staphylococcus.
  • Joint complications. Sickling in the hip bones and, less commonly, the shoulder joints, knees, and ankles can decrease oxygen flow and result in a condition called avascular or aseptic necrosis, which severely damages the joints. Symptoms include pain and problems with walking and joint movement. A person may need pain medicines, surgery, or joint replacement if symptoms persist.
  • Kidney problems. The kidneys are sensitive to the effects of red blood cell sickling. Sickle cell disease causes the kidneys to have trouble making the urine as concentrated as it should be. This may lead to a need to urinate often and to bedwetting or uncontrolled urination during the night. This often starts in childhood.
  • Leg ulcers. Sickle cell ulcers are sores that usually start small and then get larger and larger. Some ulcers will heal quickly, but others may not heal and may last for long periods of time. Some ulcers come back after healing. People who have sickle cell disease usually do not get ulcers until after age 10.
  • Liver complications. Sickle cell intrahepatic cholestasis is an uncommon but severe type of liver damage that occurs when sickled red cells block blood vessels in the liver. This blockage prevents enough oxygen from reaching liver tissue. These episodes are usually sudden and may recur. Children often recover, but some adults may have chronic problems that lead to liver failure. People who have sickle cell disease who have received frequent blood transfusions may develop liver damage from iron overload.
  • Pregnancy complications. Pregnancies in women who have sickle cell disease can increase the risk for high blood pressure and blood clots in the mother. Sickle cell disease also increases the risk for miscarriage, premature birth, and low birth weight babies.
  • Priapism, which is an unwanted, sometimes prolonged, painful erection. Priapism happens when blood flow out of the erect penis is blocked by sickled cells. Over time, priapism can cause permanent damage to the penis and lead to impotence. Priapism that lasts for more than 4 hours is a medical emergency.

Severe anemia complications
- Sickle Cell Disease

People who have sickle cell disease also usually have mild to moderate anemia. At times, however, they can have severe anemia. Severe anemia can be life-threatening. Severe anemia in a newborn or child who has sickle cell disease may be a result of:

  • Aplastic crisis. Aplastic crisis is usually caused by a parvovirus B19 infection, also called fifth disease or slapped cheek syndrome. Parvovirus B19 is a very common infection, but in sickle cell disease, it can cause the bone marrow to stop producing new red cells for a while, leading to severe anemia.
  • Splenic sequestration crisis. The spleen is an organ that is located in the upper left side of the belly. The spleen filters your blood and destroys old blood cells. In people who have sickle cell disease, red blood cells may get trapped in the spleen, making it quickly grow larger than normal. This is called splenic sequestration crisis. With red blood cells trapped in the spleen, fewer are available to circulate in the blood, and this can lead to severe anemia. A large spleen may also cause pain in the left side of the belly. A parent can usually feel a spleen that is larger than normal in a child’s belly.

Aplastic crisis and splenic sequestration crisis most commonly occur in newborns and children who have sickle cell disease. Adults who have sickle cell disease may also experience episodes of severe anemia, but these usually have other causes. Babies and newborns who have severe anemia may not want to eat and may seem very sluggish.

Look for
- Sickle Cell Disease

  • Treatment will discuss treatment-related complications or side effects.
  • Living With will explain ways to manage complications of sickle cell disease.

Diagnosis - Sickle Cell Disease

Your doctor may use a number of tests to diagnose sickle cell disease if various screening tests show that you might have the condition.

Screening tests
- Sickle Cell Disease

People who do not know whether they make sickle hemoglobin or another abnormal hemoglobin, such as SC, Sβ thalassemia, and SE, can find out by having their blood tested. This way, they can learn whether they carry a gene—or have the trait—for an abnormal hemoglobin that they could pass on to a child.

With this information, parents can be better informed about the chances of having a child with some type of sickle cell disease, such as hemoglobin SS or SC, Sβ thalassemia, or others.

Newborn screening
- Sickle Cell Disease

When a child has sickle cell disease, early diagnosis is important to better prevent complications.

Every state in the United States, the District of Columbia, and the U.S. territories require that every baby be tested for sickle cell disease as part of a newborn screening program. In newborn screening programs, blood from a heel prick is collected in “spots” on a special paper. The hemoglobin from this blood is then analyzed in special labs. Newborn screening results are sent to the doctor who ordered the test and to the child’s primary doctor.

If a baby is found to have sickle cell disease, health providers from a special follow-up newborn screening group contact the family directly to make sure that the parents know the results. The child is always retested to be sure that the diagnosis is correct.

Newborn screening programs also find out whether the baby has an abnormal hemoglobin trait. If so, the parents are informed, and counseling is offered. Remember that when a child has sickle cell trait or sickle cell disease, a future sibling or the child’s own future child may be at risk.

Prenatal screening
- Sickle Cell Disease

Doctors can also diagnose sickle cell disease before a baby is born. This is done using a sample of amniotic fluid, the liquid in the sac surrounding a growing embryo, or of tissue taken from the placenta, the organ that attaches the umbilical cord to the mother’s womb.

Testing before birth can be done as early as 8 to 10 weeks into the pregnancy. This testing looks for the sickle hemoglobin gene rather than the abnormal hemoglobin.

Reminders
- Sickle Cell Disease

Treatment - Sickle Cell Disease

A blood and bone marrow transplant is currently the only cure for some patients who have sickle cell disease. After early diagnosis, your doctor may recommend medicines or transfusions to manage complications, including chronic pain.

Babies who have sickle cell disease may see a hematologist, a doctor who specializes in blood diseases such as sickle cell disease. For newborns, the first sickle cell disease visit should take place before 8 weeks of age.

Penicilin
- Sickle Cell Disease

In children who have sickle cell disease, taking penicillin two times a day has been shown to reduce the chance of having a severe infection caused by the pneumococcus bacteria. Newborns need to take liquid penicillin. Older children can take tablets.

Many doctors will stop prescribing penicillin after a child has reached the age of 5. Some prefer to continue this antibiotic throughout life, particularly if a person has hemoglobin SS or hemoglobin Sβ0 thalassemia, since people who have sickle cell disease are still at risk. All people who have had surgical removal of the spleen, called a splenectomy, or a past infection with pneumococcus should keep taking penicillin throughout life.

Hydroxyurea
- Sickle Cell Disease

Hydroxyurea is an oral medicine that has been shown to reduce or prevent several sickle cell disease complications. This medicine was studied in patients who have sickle cell disease, because it was known to increase the amount of fetal hemoglobin (hemoglobin F) in the blood. Increased hemoglobin F provides some protection against the effects of hemoglobin S.

Hydroxyurea was later found to have several other benefits for people who have sickle cell disease, such as decreasing inflammation.

  • Use in adults. Many studies of adults with hemoglobin SS or hemoglobin Sβ thalassemia showed that hydroxyurea reduced the number of episodes of pain crises and acute chest syndrome. It also improved anemia and decreased the need for transfusions and hospital admissions.
  • Use in children. Studies in children with severe hemoglobin SS or Sβ thalassemia showed that hydroxyurea reduced the number of vaso-occlusive crises and hospitalizations. A study of children between the ages of 9 and 18 months with hemoglobin SS or Sβ thalassemia also showed that hydroxyurea reduced the number of pain episodes and dactylitis. There is no information about how safe or effective hydroxyurea is in children under 9 months of age.
  • Pregnant women should not use hydroxyurea.

Since hydroxyurea can decrease several complications of sickle cell disease, most experts recommend that children and adults with hemoglobin SS or Sβ0 thalassemia who have frequent painful episodes, recurrent chest crises, or severe anemia take hydroxyurea daily.

Hydroxyurea can cause the blood’s white cell count or platelet count to drop. Rarely, it can worsen anemia. These side effects usually go away quickly if a patient stops taking the medicine. When the patient restarts it, the doctor usually prescribes a lower dose.

It is still unclear whether hydroxyurea can cause problems later in life in people who have sickle cell disease and take the medicine for many years. Studies so far suggest that it does not put people at a higher risk of cancer and does not affect growth in children, but further studies are needed.

Transfusions
- Sickle Cell Disease

Your doctor may recommend transfusion to treat and prevent certain sickle cell disease complications. These transfusions may include:

  • Acute transfusion to treat complications that cause severe anemia. Doctors may also use transfusions when a patient has an acute stroke, in many cases of acute chest crises, and in multi-organ failure. A patient who has sickle cell disease usually receives blood transfusions before surgery, to prevent complications.
  • Red blood cell transfusions to increase the number of red blood cells and provide normal red blood cells that are more flexible than red blood cells with sickle hemoglobin.
  • Regular or ongoing blood transfusions for people who have had an acute stroke, to reduce the chances of having another stroke. Doctors also recommend blood transfusions for children who have abnormal transcranial Doppler (TCD) ultrasound results, because transfusions can reduce the chance of having a first stroke. Some doctors use this approach to treat complications that do not improve with hydroxyurea. Doctors may also use transfusions in people who have too many side effects from hydroxyurea. Possible complications include alloimmunization, which can make it hard to find a matching unit of blood for a future transfusion; infection; and iron overload.

Blood and bone marrow transplant
- Sickle Cell Disease

A blood and bone marrow transplant is currently the only cure for sickle cell disease, but it is not for everyone. Most patients who have sickle cell disease either are too old for a transplant or do not have a relative who is a good enough genetic match to be a donor. A well-matched donor is needed for a patient to have the best chance for a successful transplant.

Most sickle cell disease transplants are currently performed in children who have had complications such as strokes, acute chest crises, and recurring pain crises. These transplants usually use a matched donor. Blood and bone marrow transplants are riskier in adults.

Several medical centers are researching new sickle cell disease blood and bone marrow transplant techniques in children and adults who do not have a matched donor in the family or who are older than most recipients. Hopefully, more people who have sickle cell disease will be able to receive a transplant in the future using these new methods.

Blood and bone marrow transplants are successful in about 85 percent of cases involving children when the donor is related and HLA (human leukocyte antigen)-matched. Even with this high success rate, transplants still have risks. Complications can include severe infections, seizures, and other clinical problems. About 5 percent of people who have received such transplants have died. Sometimes transplanted cells attack the recipient’s organs. This is called graft-versus-host disease. Medicines are given to prevent many of the complications, but they still can happen.

Look for
- Sickle Cell Disease

  • Living With will explain what your doctor may recommend to manage the complications of sickle cell disease.
  • Research for Your Health will discuss how we are using current research and advancing research to treat people who have sickle cell disease.
  • Participate in NHLBI Clinical Trials will explain our open and enrolling clinical studies that are investigating treatments for sickle cell disease.

Living With - Sickle Cell Disease

If you or your child has sickle cell disease, you should learn as much as you can about the disease. It is important that you receive follow-up care and know the warning signs of complications so you know when to get medical help. Your doctor will monitor your condition and may recommend adopting healthy lifestyle changes and taking steps to prevent and control complications of sickle cell disease.

Receive routine follow-up care
- Sickle Cell Disease

Talk to your doctor about how often you should schedule follow-up visits. Most people who have sickle cell disease should see their doctor every 3 to 12 months, depending on their age. These visits will help to reduce the number of acute problems that need immediate care.

As part of your routine visits, your doctor may recommend the following vaccines to prevent infections.

  • Hepatitis. If you receive transfusions, your doctor will monitor you and give you vaccines for hepatitis.
  • Influenza. Get an influenza or flu shot every year at the start of flu season. This vaccination should begin at 6 months of age. Only the inactivated vaccine, which comes as a shot, should be used in people who have sickle cell disease.
  • Meningococcus. A child who has sickle cell disease should receive a meningococcal vaccine at 2, 4, 6, and 12 to 15 months of age. The child should receive a booster vaccine 3 years after this series of shots, then every 5 years after that.
  • Pneumococcus. Even though all children routinely receive the vaccine against pneumococcus (PCV13), your child’s doctor may recommend a second kind of vaccine against pneumococcus (PPSV23). This second vaccine is given after 24 months of age and again 5 years later. Adults who have sickle cell disease and have not received any pneumococcal vaccine should get a dose of the PCV13 vaccine. They should later receive the PPSV23 if they have not already received it or if it has been more than 5 years since they did. Follow these guidelines even if you or your child is still taking penicillin.

Learn about donating blood
- Sickle Cell Disease

People who have sickle cell disease cannot donate blood. If you have sickle cell trait, you may donate platelets, but you should not donate whole blood, as it will interfere with later steps involved in handling the donated blood.

Talk to your doctor to learn more about donating blood.

Monitor your condition
- Sickle Cell Disease

To monitor your or your child’s condition, your doctor may recommend the following tests.

  • Screening for iron overload. Your doctor will treat iron overload with chelation therapy, a medicine to reduce the amount of iron in the body and the problems that iron overload causes.
  • Height and weight to be sure that a child is growing properly and maintaining a healthy weight.
  • Oxygen saturation tests to measure how much oxygen the blood is carrying.
  • Blood tests to check for other health problems, such as anemia or organ damage.
  • Urine testing to detect early kidney problems or infections.
  • Transcranial Doppler (TCD) ultrasound screening to find out whether a child is at higher risk for stroke. When the test results are abnormal, regular blood transfusions can reduce the chances of having a stroke. This screening is recommended every year for children between the ages of 2 and 16 who have hemoglobin SS or hemoglobin Sβ0 thalassemia.
  • Eye examinations to detect sickle cell disease–related problems of the eye. Eye exams every 1 to 2 years can help doctors find and treat problems early to prevent loss of vision. A patient should see his or her doctor right away for any sudden change in vision.
  • Cognitive screening to identify problems early that may be hard to notice early in life. Sometimes these problems are caused by silent strokes that can be seen only with magnetic resonance imaging (MRI) of the brain. Tell your doctor if you have difficulties learning in school, making decisions, or organizing your thoughts.

Adopt a healthy lifestyle
- Sickle Cell Disease

Like all people, you and your child should strive to maintain a healthy lifestyle that includes:

  • Being physically active. People who have sickle cell disease often tire easily, so be careful to pace yourself and avoid very strenuous activities.
  • Getting enough sleep
  • Heart-healthy eating, including limiting alcohol. Drink extra water to avoid dehydration.
  • Quitting smoking. Visit Smoking and Your Heart and the National Heart, Lung, and Blood Institute’s Your Guide to a Healthy Heart. Although these resources focus on heart health, they include basic information about how to quit smoking. For free help and support to quit smoking, you can call the National Cancer Institute’s Smoking Quitline at 1-877-44U-QUIT (1-877-448-7848).

Learn ways to manage pain
- Sickle Cell Disease

Every patient experiences pain differently. Work with your doctor to develop a pain management plan that works for you. This often includes over-the-counter medicines, as well as stronger medicines that you get with a prescription.

Your doctor may recommend these steps to manage acute pain.

  • Talk to your doctor about taking hydroxyurea. When taken daily, hydroxyurea has been found to decrease the number and severity of pain episodes.
  • When an acute crisis is just starting, drink lots of fluids and take a nonsteroidal anti-inflammatory (NSAID) pain medicine, such as ibuprofen. If you have kidney problems, acetaminophen is often preferred. If pain persists, you may need a stronger medicine.
  • Try alternative ways to manage pain, such as massage, relaxation methods, acupuncture, or a heating pad.
  • If you cannot control the pain at home, go to a sickle cell disease day hospital/outpatient unit or an emergency room to receive additional, stronger medicines and intravenous (IV) fluids. You may be able to return home once your pain is under better control. In this case, the doctor may prescribe additional pain medicines for a short course of therapy. You may need to be admitted to the hospital to fully control an acute pain crisis.

Your doctor may recommend these steps to manage chronic pain.

  • Take pain medicines, such as ibuprofen, daily to help to reduce the pain.
  • Try massage, heat, or acupuncture.
  • Seek help if you have feelings of depression or anxiety. Supportive counseling and, sometimes, antidepressant medicines may help.

Some patients taking L-glutamine oral powder (Endari) may have fewer hospital visits or hospitalizations due to severe pain than patients who are not taking this medicine. They may also have shorter stays when they are hospitalized. More research is needed to understand how effective L-glutamine oral powder is as a treatment and which patients may benefit from using it.

Prevent and treat complications over your lifetime
- Sickle Cell Disease

To prevent and treat complications over your lifetime, your doctor may recommend the following.

  • Avoid overexertion and dehydration. Take time out to rest and drink plenty of fluids.
  • Avoid situations that may set off a crisis. Extreme heat or cold, as well as abrupt changes in temperature, are often triggers. When going swimming, ease into the water rather than jumping right in.
  • Do not travel in an aircraft cabin that is unpressurized.
  • If you experience priapism, you may be able to relieve your symptoms by doing light exercise, emptying your bladder by urinating, drinking more fluids, and taking medicine recommended by your doctor.
  • If your child attends daycare, preschool, or school, speak to his or her teacher about the disease. Teachers need to know what to watch for and how to accommodate your child.
  • Learn how to palpate, or feel, your child’s spleen. Because of the risk of splenic sequestration crisis, caretakers should learn how to palpate a child’s spleen. They should try to feel for the spleen daily and more often when the child is ill. If the spleen feels larger than usual, they should call the care provider.
  • Take your medicines as your doctor prescribes. Get any medical and lab tests or immunizations that your doctor orders.

Learn the warning signs of serious complications and have a plan
- Sickle Cell Disease

Sickle cell disease can lead to serious and life-threatening complications. If you think you or someone else is having any of the following symptoms or complications, seek medical care or call 9-1-1 immediately.

Severe anemia

See your doctor or go to a hospital right away if you develop anemia symptoms from a splenic sequestration crisis or an aplastic crisis. These conditions can be life-threatening.

Some patients may have fewer hospital visits due to sickle cell crises, including splenic sequestration, if they are taking L-glutamine oral powder, than patients who are not taking this medicine do. More research is needed to understand how effective L-glutamine oral powder is as a treatment and which patients may benefit from using it.

Fever

Having a fever when you have sickle cell disease is considered a medical emergency. All caretakers of newborns and children who have sickle cell disease should take the child to their doctor or go to a hospital right away when their child has a fever.

All children and adults who have sickle cell disease and a fever of more than 101.3 degrees Fahrenheit or 38.5 degrees Celsius must be seen by a doctor and treated with antibiotics right away. Some people will need to be hospitalized.

Acute chest syndrome

If you have symptoms of acute chest syndrome, such as chest pain, coughing, fever, and shortness of breath, see your doctor or go to a hospital right away. You will need to be admitted to the hospital, where you may receive antibiotics, oxygen therapy, or a blood transfusion.

Some patients may have fewer hospital visits due to sickle cell crises, including acute chest syndrome, if they are taking L-glutamine oral powder, than patients who are not taking this medicine do. More research is needed to understand how effective L-glutamine oral powder is as a treatment and which patients may benefit from using it.

Stroke

If you think someone may be having a stroke, act F.A.S.T.

F—Face: Ask the person to smile. Does one side of the face droop?

A—Arms: Ask the person to raise both arms. Does one arm drift downward?

S—Speech: Ask the person to repeat a simple phrase. Is their speech slurred or strange?

T—Time: If you observe any of these signs, call for help immediately. Early treatment is essential.

Read more about the signs and symptoms of a stroke.

If imaging studies reveal an acute stroke, you may need an exchange transfusion. This procedure involves slowly removing a certain amount of your blood and replacing it with blood from a donor who does not have sickle cell disease or sickle cell trait. Afterward, you may need to receive monthly transfusions or other treatments to help to prevent another stroke.

Priapism

If you experience priapism that lasts for 4 hours or more, go to the hospital to see a hematologist and urologist.

Some patients may have fewer hospital visits due to sickle cell crises, including priapism, if they are taking L-glutamine oral powder, compared with patients who are not taking this medicine. More research is needed to understand how effective L-glutamine oral powder is as a treatment and which patients may benefit from using it.

Return to Signs, Symptoms, and Complications to review possible complications from sickle cell disease.

Transition to adult care
- Sickle Cell Disease

The move from pediatric care to adult care is an important step in treatment. Talk with your teen’s healthcare team about creating a plan to help your teen transition to adult care. This period has been shown to be associated with greater numbers of hospital admissions and medical problems. There seem to be many reasons for this.

  • Some of the increased risk is directly related to the disease. As people who have sickle cell disease get older, they often develop more organ damage and more disabilities.
  • The shift in care usually occurs at the same time that adolescents are undergoing many changes in their emotional, social, and academic lives. The transition to more independent self-management may be difficult, and following treatment plans may become less likely.
  • Compared with pediatrics, there are often fewer adult sickle cell disease programs available in a given region. This makes it more difficult for a person who has sickle cell disease to find appropriate doctors, particularly doctors with whom they feel comfortable.

To improve use of regular medical care by people who have sickle cell disease and to reduce age-related complications, many sickle cell disease teams have developed special programs that make the transition easier. Such programs should involve the pediatric and adult care teams.

Pregnancy
- Sickle Cell Disease

Pregnant women who have sickle cell disease are at greater risk for problems. If you are pregnant or are planning to become pregnant, see an obstetrician (a doctor who specializes in pregnancy and childbirth) who has experience with patients who have sickle cell disease and with high-risk pregnancies and deliveries.

Pregnant women who have sickle cell disease need more frequent medical visits. Your doctor may prescribe certain vitamins and will be careful to prescribe pain medicines that are safe for your baby.

You may need to have one or more blood transfusions during pregnancy to treat complications, such as worsening anemia or an increased number of pain or acute chest syndrome events.

You should not use hydroxyurea during pregnancy.

Take care of your mental health
- Sickle Cell Disease

Living with sickle cell disease can be very stressful. At times, you may feel sad or depressed. Talking about how you feel with your or your child’s healthcare team may help. Your doctor may recommend:

  • Medicines or other treatments, such as antidepressants, or other treatments that can improve your quality of life
  • Joining a patient support group, which may help you or your child adjust to living with sickle cell disease. You can see how other patients manage similar symptoms and their condition. Talk with your doctor about local support groups or check with an area medical center.
  • Support from family and friends, which can help relieve stress and anxiety. Let your loved ones know how you feel and what they can do to help you.

Research for Your Health

The NHLBI is part of the U.S. Department of Health and Human Services’ National Institutes of Health (NIH)—the nation’s biomedical research agency that makes important scientific discoveries to improve health and save lives. We are committed to advancing science and translating discoveries into clinical practice to promote the prevention and treatment of heart, lung, blood, and sleep disorders, including sickle cell disease. Learn about current and future NHLBI efforts to improve health through research and scientific discovery.

Improving health with current research
- Sickle Cell Disease

Learn about some of the ways we continue to translate current research into improved health for patients who have sickle cell disease. Research on this topic is part of the NHLBI’s broader commitment to advancing blood disorders and blood safety scientific discovery.

  • Accelerating Cures for All People Who Have Sickle Cell Disease. Our Cure Sickle Cell Initiative is an NHLBI-led collaborative research effort to develop genetic therapies for patients who have sickle cell disease. The goal is to have these genetic therapies ready to safely use in clinical research within five to 10 years. The Initiative is patient-focused, and it will bring together researchers, private sector researchers, patients, providers, advocacy groups, and others as it supports research, education, and community engagement activities.
  • A Legacy of Research Excellence. We have supported research on sickle cell disease since our founding in 1948. With each decade since, the NHLBI has kept a sustained focus on advancing the understanding of sickle cell disease and improving clinical care. The NHLBI is committed to building on its legacy of research excellence to find new treatments, cures, and personalized care for the approximately 100,000 Americans and over 20 million people worldwide who have sickle cell disease. Visit Sickle Cell Disease: A Legacy of Research Excellence for more information.
  • Using Large NHLBI Studies to Better Understand Sickle Cell Trait and the Risk of Stroke. NHLBI-funded researchers are studying stroke in African Americans who participated in large NHLBI-funded cardiovascular studies, such as our Jackson Heart Study, the Women’s Health Initiative, and the Multi-Ethnic Study of Atherosclerosis . Researchers found that African Americans who have sickle cell trait were not at an increased risk of stroke.
  • Annual Sickle Cell Disease Clinical Research Meetings. Each year, we bring together researchers and health professionals to discuss clinical trials, research, and clinical care for sickle cell disease. Explore resources from the 2016 annual meeting.
  • Global Leadership in Sickle Cell Disease Research and Care. More than 75 percent of newborns who have sickle cell disease are born in sub-Saharan Africa. By funding the Sickle Cell Disease in Sub-Saharan Africa Collaborative Consortium and associated Data Coordinating Center, we are building the regional capabilities to research sickle cell disease and monitor patients in Africa. We are also collaborating with other NIH Institutes and Centers in Human Heredity and Health in Africa (H3Africa) projects. We also support development of an inexpensive and simple screening test for use in sub-Saharan Africa, an area where medical resources and access to newborn screening tests are limited. The test can lead to earlier diagnoses and treatment for children who have sickle cell disease in these areas. Read Rapid Result Test On Track to Transform Sickle Cell Disease Screening for Millions to learn more.
  • Advancing research on sickle cell treatment from the laboratory to clinical trials. NHLBI funding supports research on a new medicine for sickle cell disease to increase healthy fetal hemoglobin that can replace the sickle cell hemoglobin. Read NHLBI research grants advance sickle cell treatment from lab to patients to learn more.

Learn about the pioneering research contributions we have made over the years that have improved clinical care and increased life expectancy for people who have sickle cell disease.

Advancing research for improved health
- Sickle Cell Disease

In support of our mission, we are committed to advancing sickle cell disease research in part through the following ways.

Learn about other exciting ways we are advancing research to improve the lives of people with sickle cell disease.

Participate in NHLBI Clinical Trials

We lead or sponsor many studies on sickle cell disease. See whether you or someone you know is eligible to participate in our clinical trials.

Trials at the NIH Clinical Center

Sickle cell disease and kidney function tests

This study will compare two different lab tests to measure kidney function in adults with sickle cell disease. Participants in this study must be at least 18 years old and cannot have experienced a pain crisis in the last month or a change in treatment in the last 2 months. This study is located in Bethesda, Maryland.

Pregnancy and umbilical cord donation for sickle cell disease

This study seeks to determine the best way to collect, store, and handle blood from newborns to help researchers improve future sickle cell disease therapies. To participate in this study, you must be pregnant, 45 years old or younger, and willing to donate umbilical cord blood from your newborn. Newborns may be healthy or at risk for sickle cell disease or sickle cell trait. This study is located in Bethesda, Maryland.

Blood samples for genetic testing

This study will look at whether a particular gene in people who have sickle cell disease increases the risk for more severe symptoms and complications. To participate in this study, you must be between 18 and 80 and not have had a blood transfusion in the previous 8 weeks. This study is located in Bethesda, Maryland.

Bone marrow transplant procedures for severe anemia

This study aims to improve bone marrow transplant (BMT) procedures for older patients by using a low dose of radiation and two immunosuppressive drugs instead of chemotherapy. This type of BMT procedure is described as nonmyeloablative because it does not destroy bone marrow. Participants in this study must be between 2 and 65 years old; have a severe congenital anemia, such as sickle cell disease or beta thalassemia; and have a sibling who is a well-matched stem cell donor. This study is located in Bethesda, Maryland.

Pain crises and lung complications in sickle cell disease

This study is interested in understanding pain crises and lung complications that occur in sickle cell disease patients and patients who have other red blood cell disorders. To participate in this study, you must be at least 2 years old with known or suspected sickle cell disease, sickle cell trait, or other red blood cell disorders. Participants will have a physical exam and receive standard medical care for sickle cell disease, including routine follow-up tests and procedures. This study is located in Washington, D.C., and Bethesda, Maryland.
View more information about Natural History of Sickle Cell Disease.

Stem cell transplant procedure with a partial match

This study is testing new ways to improve a stem cell transplant procedure that involves a donor who is not a complete match, called a partial match. To participate in this study, you must be at least 18 years old and have both severe sickle cell disease and a donor who is a partial match. This study is located in Bethesda, Maryland.

Improving bone marrow transplants

This study is exploring how to improve bone marrow transplant procedures so the body better accepts donor stem cells. To participate in this study, you must be at least 4 years old, have sickle cell disease, and have a stem cell donor. This study is located in Bethesda, Maryland.

Pain crises and sickle cell disease

This study is exploring the biology behind pain crises in patients who have sickle cell disease. To participate in this study, you must be between 18 and 80 years old and not be pregnant or on certain treatments that affect your immune system. This study is located in Bethesda, Maryland.

Blood disorder research

This study is collecting medical information from health exams and routine tests and procedures to see whether participants may be able to enroll in other studies on blood disorders. Participants in this study must be at least 8 years, with or without a blood disorder. This study is located in Bethesda, Maryland.

To learn more about clinical trials at the NIH Clinical Center or to talk to someone about a study that might fit your needs, call the Office of Patient Recruitment 800-411-1222.

Do you or your child have HbSS or Sβ0 thalassemia, and are you or your child willing to provide blood and urine samples during a pain crisis?

This study will look at whether changes in blood and urine can be used to monitor whether acute kidney injury has developed as a result of a pain crisis or acute chest syndrome. Participants in this study must be between 1 and 25 years old and be admitted with a pain crisis or acute chest syndrome. This study is located in Birmingham, Alabama.

Are you or your child interested in donating a sample of bone marrow for research?

This study will collect samples of bone marrow from patients who have sickle cell disease or β-thalassemia to help develop genetic therapies. Participants in this study must be at least 2 years old and have sickle cell disease or β-thalassemia. You may continue regular treatments while participating in the study. This study is located in Memphis, Tennessee.
View more information about Bone Marrow for Hemoglobinopathy Research.

Are you 15 to 40 years old and have severe sickle cell disease?

This study is comparing long-term outcomes for patients who receive blood and bone marrow transplants and those who receive standard treatment with medicines. Participants also have an option of contributing blood samples to be stored for future research. Participants must be 15 to 40 years old and have severe sickle cell disease. This study is located in Madison, Wisconsin.

Do you have sickle cell disease or thalassemia, or are you a healthy volunteer who is willing to undergo a brain MRI?

This study aims to understand whether sickle cell disease or thalassemia affects the processes that naturally increase blood flow in the brain when people experience stress. Researchers will measure blood flow using brain magnetic resonance imaging (MRI). Participants in this study must be at least 7 years old and have sickle cell disease or thalassemia. Healthy volunteers can also participate. This study is located in Los Angeles, California.

Are you an adult who has chronic pain from sickle cell disease?

This study is testing a new computer-based program that aims to help patients who have sickle cell disease manage pain. Participants must be at least 18 years old and have chronic pain. This study is located in Pittsburgh, Pennsylvania.

Do you or your child have severe sickle cell disease and also know a half-matched bone marrow donor?

This study is seeking to improve bone marrow transplantation success from half-matched donors by testing a different conditioning procedure that uses a variety of medicines to prepare for the transplant. To participate in this study, you must be 15 to 45 years old and have severe sickle cell disease or have a child 5 to 14 years old who has had a stroke. This study is located in many sites across the United States, including Miami, Florida, and St. Louis, Missouri.

Are you an adult who has sickle cell disease and wheezing not caused by asthma?

This study will test an inhaled medicine called mometasone for people who have sickle cell disease and wheezing that is not caused by asthma. To participate in this study, you must be at least 18 years old and not have asthma, acute respiratory symptoms, or a current pain crisis. This study is located in New York, New York.

Do you have a child 12 to 18 years old who has sickle cell disease and is interested in hypnosis?

This study is testing whether hypnosis has an effect on blood flow and pain in adolescents who have sickle cell disease. To participate in this study, you must be between 12 and 18 years old and be fluent in English. This study is located in Los Angeles, California.

Are you between 16 and 20 years old and willing to answer questions about managing your sickle cell disease?

This study is investigating the care and quality of life of patients who have sickle cell disease as they transition from pediatric to adult care. To participate in this study, you must be between 16 and 20 years old and be a patient of St. Jude Children’s Research Hospital. This study is located in Memphis, Tennessee.

Do you or your child have sickle cell disease and high blood pressure?

This study is exploring whether use of losartan, a medicine commonly used to lower blood pressure, is effective at treating abnormal nighttime blood pressure in children and young adults who have sickle cell disease. Participants in this study must be between 5 and 25 years old and have high blood pressure and a certain type of sickle cell disease: hemoglobin SS or Sβ0 thalassemia. This study is located in Birmingham, Alabama.
View more information about Preventing Sickle Cell Kidney Disease.

Do you have sickle cell disease and an interest in providing information that can help develop a mobile app?

This study is investigating why patients who have sickle cell disease may not be able to take hydroxyurea or have challenges taking it. This will help researchers develop a mobile application that helps patients take their medicine as directed. To participate in this study, you must be between 15 and 45 years old, have sickle cell disease, and be able to speak English. This study is located in Memphis, Tennessee.

Do you or your child have sickle cell disease and also have an interest in contributing to long-term data collection?

This study is monitoring patients and collecting biological samples from patients who have sickle cell disease to better understand long-term outcomes. Participants can be any age and must have sickle cell disease. This study is located in six sites in Illinois, Louisiana, North Carolina, and Tennessee.

Are you an adult who has pain from sickle cell disease and has trouble sleeping?

This study will look at whether improving sleep also reduces pain in people who have sickle cell disease and chronic pain. Participants in this study must be at least 18 years old, have diagnosed sickle cell disease, and experience insomnia and chronic pain. This study is located in Baltimore, Maryland.
View more information about Sleep and Pain in Sickle Cell Disease.

Do you or your child need a stem cell transplant?

This study is exploring the use of treatment with certain medicines in combination with radiation for a successful stem cell transplant. To participate in this study, you must be younger than 49 years old and have a severe disease treatable by a stem cell transplant. This study is located in several sites across the United States, including Aurora, Colorado; Seattle, Washington; and Milwaukee, Wisconsin.

More Information

After reading our Sickle Cell Disease Health Topic, you may be interested in additional information found in the following resources.

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