A stroke happens when blood flow to the brain is blocked. This prevents the brain from getting oxygen and nutrients from the blood. Without oxygen and nutrients, brain cells begin to die within minutes. Sudden bleeding in the brain can also cause a stroke if it damages brain cells.
A stroke is a medical emergency. A stroke can cause lasting brain damage, long-term disability, or even death. Signs of a stroke can range from mild weakness to paralysis or numbness on one side of the face or body. Other signs include a sudden and severe headache, sudden weakness, trouble seeing, and trouble speaking or understanding speech.
If you think you or someone else is having a stroke, call 9-1-1 right away. Do not drive to the hospital or let someone else drive you. Call an ambulance so that medical personnel can begin life-saving treatment on the way to the emergency room. During a stroke, every minute counts.
At the hospital, a stroke team will assess your condition and treat your stroke with medicine, surgery, or another procedure. Your recovery will depend on how severe your stroke was and how quickly you got treatment. A rehabilitation plan may help you do the same things you used to do before your stroke.
Explore this Health Topic to learn more about stroke, our role in research and clinical trials, and where to find more information.
Causes - Stroke
There are two main types of stroke that have different causes. Ischemic strokes are caused by a blockage of a blood vessel. Hemorrhagic strokes are caused by sudden bleeding in the brain. Sometimes the doctor may not be able to figure out the cause of your stroke.
Ischemic strokes are usually caused by a piece of or a blood clot that blocks blood flow to the brain.
When a fatty substance called plaque builds up on the inner walls of the arteries, it can lead to a disease called atherosclerosis. Plaque hardens and narrows the arteries, which limits blood flow to tissues and organs.
Plaque can build up in any artery in the body, including arteries in the brain and neck. Carotid artery disease is when plaque builds up in the carotid arteries in the neck that supply blood to the brain. It is a common cause of ischemic stroke.
Blood clots in the brain or elsewhere in the body
Plaque in an artery can break open. Blood stick to the site of the plaque injury and clump together to form blood clots. These clots can partly or fully block an artery.
A blood clot that forms in one part of the body can also break loose and travel to the brain. This type of ischemic stroke is called an embolic stroke. Certain heart and blood conditions, such as atrial fibrillation and sickle cell disease, can cause blood clots that lead to stroke.
Chronic (long-term) contributes to ischemic stroke. Researchers are still trying to understand this fully. We know that inflammation can damage the blood vessels and contribute to atherosclerosis, however. In addition, ischemic stroke can lead to inflammation that further damages brain cells.
Transient ischemic attack
A transient ischemic attack (TIA) is caused by a blockage in the brain just like an ischemic stroke. But the blockage breaks up before there is any damage to your brain. It typically lasts less than an hour but can come and go. Eventually, it can progress to a full stroke. A TIA is also called a mini-stroke.
Sudden bleeding can cause a hemorrhagic stroke. This can happen when an artery in or on top of the brain breaks open. The leaked blood causes the brain to swell, putting pressure on it that can damage brain cells.
Some conditions make blood vessels in the brain more likely to bleed.
- Aneurysm is a balloon-like bulge in an artery that can stretch and burst.
- Arteriovenous malformations (AVMs) are tangles of poorly formed arteries and veins that can break open in the brain.
- High blood pressure puts pressure on the inside walls of the arteries. This pressure makes them more likely to break open, especially when they are weakened because of an aneurysm or AVM.
Risk Factors - Stroke
There are many risk factors for stroke. You can treat or control some of your risk factors, such as high blood pressure and smoking. But you cannot control others such as your age or sudden changes in your health—for example, if you have an aneurysm.
The major risk factors for stroke include:
- High blood pressure
- Heart and blood vessel diseases. Conditions that can cause blood clots or other blockages include coronary heart disease, atrial fibrillation, heart valve disease, and carotid artery disease.
- High levels
- Brain aneurysms or arteriovenous malformations (AVMs). AVMs are tangles of poorly formed arteries and veins that can break open in the brain.
- Viral Infections or conditions that cause inflammation, such as lupus or rheumatoid arthritis. Watch our video to learn more about how SARS-Cov-2, the virus responsible for COVID-19, may raise the risk of stroke.(Merkler, 2020) Additionally, we offer information and resources on how we are working hard to support necessary COVID-19 research.
- Age. A stroke can happen at any age, but the risk is higher for babies under the age of 1 and for adults. In adults, the risk increases with age.
- Sex. At younger ages, men are more likely than women to have a stroke. But women tend to live longer, so their lifetime risk of having a stroke is higher. Women who take birth control pills or use hormone replacement therapy are at higher risk. Women are also at higher risk during pregnancy and in the weeks after giving birth. High blood pressure during pregnancy—such as from preeclampsia—raises the risk of stroke later in life.
- Race and ethnicity. In the United States, stroke occurs more often in African American, Alaska Native, American Indian, and Hispanic adults than in white adults.
- Family history and . Your risk of having a stroke is higher if a parent or other family member has had a stroke, particularly at a younger age. Certain genes affect your stroke risk, including those that determine your blood type. People with blood type AB (which is not common) have a higher risk.
Other risk factors for stroke—some of which you can control—include:
- Anxiety, depression, and high stress levels. Working long hours and not having much contact with friends, family, or others outside the home are also linked with higher risk of stroke.
- Living or working in areas with air pollution.
- Other medical conditions, such as certain bleeding disorders, sleep apnea, kidney disease, migraine headaches, and sickle cell disease.
- Blood-thinners or other medicines that can lead to bleeding.
- Other unhealthy lifestyle habits, including eating unhealthy foods, not getting regular physical activity, drinking alcohol, getting too much sleep (more than 9 hours), and using illegal drugs such as cocaine.
- Overweight and obesity or carrying extra weight around your waist and stomach.
Signs, Symptoms, and Complications - Stroke
The signs and symptoms of a stroke often develop quickly. However, they can develop over hours or even days, such as when a transient ischemic attack (TIA) turns into a stroke.
The type of symptoms depends on the type of stroke and the area of the brain that is affected.
Signs and symptoms of a TIA or stroke may include:
- Sudden numbness or weakness, especially on one side of the body
- Sudden confusion or trouble speaking or understanding speech
- Sudden trouble seeing in one or both eyes
- Sudden trouble walking, dizziness, or loss of balance or coordination
- Sudden severe headache with no known cause
The FAST test can help you remember what to do if you think someone may be having a stroke:
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 9-1-1 right away. Early treatment is essential.
If you think you or someone else is having a TIA or stroke, don’t drive to the hospital or let someone else drive you. Call an ambulance so that medical personnel can begin life-saving treatment on the way to the emergency room. During a stroke, every minute counts.
A stroke can cause lasting brain damage, long-term disability, or even death. When you have a stroke, your doctor may rate how severe it is. A more severe stroke means more brain tissue was damaged. When there has been significant damage, your doctor may call it a massive stroke. This can mean more severe complications.
After having a stroke, you may develop complications such as:
- Dangerous blood clots. Being unable to move around for a long time can raise your risk of developing blood clots in the deep veins of the legs. In some cases, blood clots can break loose and travel to the lungs. Your stroke care team may try to prevent these complications with medicine or a device that puts pressure on your calves to keep your blood flowing.
- Difficulty speaking. If a stroke affects the muscles you use to speak, you may have trouble communicating as easily as before.
- Loss of bladder or bowel control. Some strokes affect the muscles used to urinate and have bowel movements. You may need a urinary catheter (a tube placed into the bladder) until you can urinate on your own. Use of these catheters can lead to urinary tract infections. You may also lose control of your bowels or be constipated.
- Loss of bone density or strength. This usually happens on one side of the body. Physical activity as part of rehabilitation can help prevent this loss. Your care team may also evaluate you for osteoporosis.
- Loss of vision, hearing, or touch. Your ability to feel pain or temperature may be affected after a stroke, or you may have trouble seeing or hearing as well as before. Some of these changes could affect your ability to cook, read, change your clothes, or do other tasks.
- Muscle weakness or inability to move. A stroke can make your muscles become weak and stiff or cause them to spasm. This can be painful or make it hard to stand or walk around on your own. You may also have problems with balance or controlling your muscles. This puts you at risk of falling.
- Problems swallowing and pneumonia. If a stroke affects the muscles used for swallowing, you may have a hard time eating or drinking. You may also be at risk of inhaling food or drink into your lungs. If this happens, you may develop pneumonia.
- Problems with language, thinking, or memory. Stroke may affect your ability to focus on a task or make decisions quickly. It also raises the risk of dementia.
- Seizures. This is more common in the weeks after a stroke and is less likely as time goes on. If you have seizures, your stroke team may give you medicine.
- Swelling in the brain. After a stroke, fluid may build up between the brain and the skull or in the cavities of the brain, causing swelling. Doctors may drain fluid from the brain or cut away part of the skull to relieve the pressure on your brain.
Diagnosis - Stroke
Your doctor will diagnose a stroke based on your signs and symptoms, your medical history, a physical exam, and test results. Your doctor will want to find out the type of stroke you’ve had, its cause, the part of the brain that is affected, and whether you have bleeding in the brain. If your doctor thinks you’ve had a transient ischemic attack (TIA), he or she will look for its cause to help prevent a future stroke.
Medical history and physical exam
Your doctor will ask you or a family member about your risk factors for stroke. Tell your doctor if you or someone in your family has had a stroke. Your doctor will also ask about your signs and symptoms and when they began.
During the physical exam, your doctor will check you for:
- Coordination and balance
- Mental alertness
- Numbness or weakness in your face, arms, and legs
- Trouble speaking or seeing clearly
The exam will help your doctor determine how severe your stroke was and plan your treatment.
Your doctor will look for signs of carotid artery disease, a common cause of ischemic stroke. He or she will listen to your carotid arteries with a stethoscope. A whooshing sound called a bruit may suggest changed or reduced blood flow due to plaque buildup in the carotid arteries.
Diagnostic tests and procedures
Your doctor will order tests to help rule out other health problems with similar signs or symptoms.
Your doctor will order an imaging test to look at the blood vessels in your brain. This will help determine what type of stroke you have and where exactly it happened. The quicker these tests can be done, the better your doctor can treat you. Tests to diagnose stroke include the following:
- Computed tomography (CT) uses X-rays to take clear, detailed pictures of your brain. It is often done right after a stroke is suspected. A brain CT scan can show if there is bleeding in the brain or damage to the brain cells from a stroke.
- Magnetic resonance imaging (MRI) uses magnets and radio waves to create pictures of your brain. An MRI may be used instead of—or in addition to—a CT scan to diagnose a stroke. This test can detect changes in brain tissue and damage to brain cells.
- Other imaging tests to look for narrowed blood vessels in the neck or an aneurysm or tangled blood vessels in the brain.
Your doctor may also order the following blood or heart tests.
- Blood tests. Your doctor may test the blood and platelet count and glucose (sugar) levels in your blood to make sure they are stable and to see if a certain medicine can treat your stroke. Your doctor may also do blood tests to see how well your blood is clotting and to look for muscle damage.
- Electrocardiogram (EKG). An EKG can help detect heart problems that may have led to a stroke. For example, this test can help diagnose atrial fibrillation or a previous heart attack.
- Lumbar puncture (also called a spinal tap), if the imaging scan does not detect any bleeding in the brain but your doctor still thinks you may have had a hemorrhagic stroke. The doctor will use a needle to collect fluid from around your spine. The fluid will be tested for substances from broken-down blood cells.
Treatment - Stroke
A stroke requires emergency care. You will probably receive treatment in a specialized stroke unit of the hospital. A team of specialists will oversee your care. Treatment will depend on whether the stroke was ischemic or hemorrhagic, how much time has passed since symptoms began, and whether you have other medical conditions.
Treating an ischemic stroke
Treatment for an ischemic stroke or transient ischemic (TIA) may include medicines and medical procedures.
The main treatment for an ischemic stroke is a medicine called tissue plasminogen activator (tPA). It breaks up the blood clots that block blood flow to your brain. A doctor will inject tPA into a vein in your arm. This type of medicine must be given within 3 hours after your symptoms start. In some cases, it is given up to 4.5 hours. The sooner treatment begins, the better your chances of recovery.
If you cannot have tPA, your doctor may give an anticoagulant or blood thinning medicine, such as aspirin or clopidrogrel. This helps stop blood clots from forming or getting larger. The main side effect of these medicines is bleeding.
You may need a procedure to open up blocked arteries and restore blood flow to the brain. This can be done several ways.
A thrombectomy removes the clot from the blood vessel. A surgeon will put a long, flexible tube called a catheter into your groin (upper thigh) and thread it to the blocked artery in your neck or brain. They will then use angioplasty and stenting or a device called a stent retriever to open up the blocked artery.
- Angioplasty and stenting procedures use a thin tube to deliver a balloon or small mesh tube into the artery. Inflating the balloon or expanding the mesh tube clears space for blood to flow more easily to the brain.
- The stent retriever is a wire mesh inside the catheter that traps the clot. The stent retriever and the blood clot are then pulled out through the tube.
If carotid artery disease caused your stroke, your doctor may suggest carotid endarterectomy, a surgery to remove plaque from the carotid artery in your neck. Visit our Carotid Artery Disease Health Topic to learn more about how these procedures work.
Treating a hemorrhagic stroke
Hemorrhagic stroke can happen suddenly and grow worse quickly. Just as with an ischemic stroke, getting treatment as quickly as possible is essential for a full recovery. The type of treatment you receive depends on what part of your brain is bleeding and how severe it is.
You may be given blood pressure medicine to lower the pressure and strain on blood vessels in the brain. You will also be taken off any anticoagulant or blood-thinning medicines that may have led to bleeding. Depending on the type of medicine you were taking, you may be given vitamin K to help stop bleeding.
Procedures may include:
- Aneurysm clipping to block off the aneurysm from the blood vessels in the brain. This surgery helps stop bleeding from an aneurysm. It can also help prevent the aneurysm from bursting again. During the procedure, a surgeon places a tiny clamp at the base of the aneurysm.
- Coil embolization to block blood flow to or seal an aneurysm. The surgeon will insert a tube called a catheter into an artery in the groin. He or she will thread the tube to the aneurysm in your brain. A tiny coil will be pushed through the tube and into the aneurysm. The coil will cause a blood clot to form, which will block blood flow through the aneurysm and prevent it from bursting again.
- Blood transfusion
- Draining excess fluid that collects in the brain. Fluid can build up after a stroke, pushing the brain against the skull and causing damage. Draining the fluid can relieve that pressure.
- Surgery or radiation to remove or shrink an arteriovenous malformation (AVM). An AVM is a tangle of arteries and veins that can break open in the brain.
- Surgery to remove pooled blood. Typically, the stroke team will use surgery only if you show signs of getting worse.
- Surgery to temporarily remove part of the skull, if you have a lot of swelling. This allows room for the brain to swell without putting pressure on the brain.
Other care you may receive in the hospital
In addition to treating the blockage or bleeding causing the stroke, your healthcare team may suggest additional treatments or tests.
- Breathing support. If your stroke makes it difficult to breathe or your oxygen levels are low, you may receive ventilator support.
- Compression therapy. A sleeve can be placed on your leg and filled with air to reduce the risk of venous thromboembolism.
- Feeding tube. If it is difficult for you to swallow on your own, your team may set up a feeding tube to provide you with nutrients.
- Fluids. If you have low blood pressure or low blood volume, you may get fluids to restore proper levels.
- Medicine to reduce fever. Your team will monitor your body temperature and may give you acetaminophen or another medicine to reduce fever and prevent additional brain damage.
- Rehabilitation plan. Before you leave the hospital, your medical team will test how well you can speak, swallow, and walk. You and your medical team can work together to set up a rehabilitation plan.
- Skin care. To prevent skin irritation or sores from forming, your team will help make sure that you have enough cushioning, your skin stays dry, and that you change positions often if you cannot move well on your own.
Stroke is a life-threatening condition that can cause severe disability. or care may help some patients have a better quality of life with fewer symptoms.
Life After a Stroke - Stroke
It can take weeks, months, or even years to recover from a stroke. Some people recover fully, while others have long-term or lifelong disabilities. A stroke team will work with you to manage your care. Your team may include specialists in neurology (brain, spinal cord, and nerves), rehabilitation, or mental health. You will also want to take steps to prevent another stroke and be aware of possible long-term complications. Call 9-1-1 if you have any signs of another stroke.
Healthy lifestyle changes
Heart-healthy lifestyle changes can help you recover from a stroke and may help prevent another one.
- Choose heart-healthy foods
- Aim for a healthy weight
- Manage stress
- Get regular physical activity
- Quit smoking
- Get enough good-quality sleep
Monitor your condition
It is important to get routine medical care after your stroke. Follow your treatment plan and talk with your doctor about how often you should schedule office visits.
- Talk with your doctor about the level of care you need. Some people return home after leaving the hospital. Others receive ongoing care at another facility.
- Take all medicines as prescribed. If heart-healthy lifestyle changes are not enough, your doctor may recommend medicine to control high blood pressure or cholesterol. Your doctor may also recommend aspirin or other medicine to prevent dangerous clotting that could lead to another stroke. Do not change the amount of your medicine or skip a dose.
After a stroke, you may need rehabilitation (rehab) to help you recover. Rehab may include working with speech, physical, and occupational therapists. Your care team may also recommend medicines to manage pain, muscle spasms, or other problems as you recover.
- Language, speech, and memory. You may have trouble communicating after a stroke. You may not be able to find the right words, put complete sentences together, or put words together in a way that makes sense. You may also have problems with your memory and thinking clearly. These problems can be very frustrating. Speech and language therapists can help you learn ways to communicate again and improve your memory.
- Muscle and nerve problems. A stroke may affect only one side of the body or part of one side. It can cause muscle weakness or paralysis, which can put you at risk for falling. Trouble using your hands, arms, and fingers is common, and training may help if you can no longer walk easily. Physical and occupational therapists can help you strengthen and stretch your muscles. They can also help you relearn how to do daily activities, such as dressing, eating, and bathing.
- Bladder and bowel problems. A stroke can affect the muscles and nerves that control the bladder and bowels. You may feel like you have to urinate often, even if your bladder is not full. You may not be able to get to the bathroom in time. Medicines and a bladder or bowel specialist can help with these problems.
- Swallowing and eating problems. You may have trouble swallowing after a stroke. Signs of this problem are coughing or choking during eating or coughing up food after eating. A speech therapist can help you with these issues. He or she may suggest changes to your eating plan, such as chopping up your food or drinking thick liquids.
Canes, braces, grab bars, special eating utensils, wheelchairs, and other devices can make it easier to keep doing your regular activities after a stroke.
Take care of your mental health
After a stroke, you may have changes in your behavior or judgment. For example, your mood may change quickly. Because of these and other changes, you may feel scared, anxious, and depressed. Recovering from a stroke can be slow and frustrating. Some people develop symptoms of post-traumatic stress disorder (PTSD).
Talk about how you feel with your healthcare team. Your doctor may recommend:
- Joining a patient support group, which may help you adjust to life after a stroke. You can see how other people manage similar symptoms and their condition. Talk with your doctor about local support groups or check with an area medical center.
- Medicines, such as antidepressants, or other treatments that can improve your quality of life.
- 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.
Prevent another event
Your doctor may recommend strategies to help prevent another stroke. This will depend on what caused your first stroke.
- Carotid endarterectomy. Your doctor may recommend this if you have carotid artery disease.
- Medicine or surgery for a heart condition. Blood thinners can help reduce the risk of another stroke due to atrial fibrillation. If you have a congenital heart defect that makes it easier for blood clots to travel to the brain, your doctor may suggest surgery to fix the problem.
If you recognize any signs of stroke, call 9-1-1 right away.
Learn the warning signs of serious complications and have a plan
The most common side effect of taking blood thinners to reduce your stroke risk is bleeding. This happens if the medicine thins your blood too much. This side effect can be life-threatening. Bleeding can occur inside your body cavities or from the surface of your skin.
Know the warning signs of bleeding so you can get help right away. They include:
- Blood in your urine, bright red blood in your stools, or black tarry stools
- Bright red vomit or vomit that looks like coffee grounds
- Increased menstrual flow
- Pain in your abdomen or severe pain in your head
- Unexplained bleeding from the gums and nose
- Unexplained bruising or tiny red or purple dots on the skin
Easy bruising or bleeding may mean that your blood is too thin. Call your doctor right away if you have any of these signs. If you have severe bleeding, call 9-1-1.
Research for Your Health
Improving health with current research
Learn about the following ways the NHLBI continues to translate current research into ways to prevent, diagnose, and treat stroke. Research on this topic is part of the NHLBI’s broader commitment to advancing heart and vascular diseases scientific discovery.
- NHLBI’s Legacy of Stroke Research, Anchored in Landmark Framingham Study. NHLBI’s landmark Framingham Heart Study (FHS), launched in 1948, has contributed transformative discoveries for heart and blood vessel diseases such as stroke. This includes the identification of high blood pressure and atrial fibrillation as risk factors for stroke. Through the FHS, scientists learned that many of those risk factors can be changed. Such findings are paving the way for new interventions to prevent, diagnose, or treat these conditions more effectively. The data also helped researchers develop a risk calculator to estimate the risk of stroke or other conditions.
- Shaping Treatment Guidelines through the Systolic Blood Pressure Intervention Trial (SPRINT) Study. SPRINT is a major long-term research effort supported by the NHLBI that investigates the effect of high blood pressure treatment on outcomes such as stroke. The SPRINT study found that treating to a lower systolic blood pressure target—less than 120 mm Hg—reduced stroke deaths caused by high blood pressure. SPRINT results informed recent high blood pressure clinical guidelines that aim to improve treatment for millions of people.
- The Multi-Ethnic Study of Atherosclerosis (MESA). MESA is an NHLBI-sponsored study of atherosclerosis, spanning two decades in six U.S. communities, that has helped us learn about the causes and results of plaque buildup. For example, NHLBI researchers using MESA data found a link between early menopause and risk of stroke. Women in the study who experienced menopause before age 46 were twice as likely to develop a stroke as women who did not have early menopause.
- Understanding Differences in Stroke Burden. The NIH REasons for Geographic and Racial Differences in Stroke (REGARDS) Study enrolled more than 30,000 participants from 2003 to 2007 to understand why the rate of stroke deaths was higher in the southeastern United States and among African Americans. For example, NHLBI-supported analyses showed that gum disease, which causes inflammation, is more common in African Americans and is linked with stroke. In addition, African Americans in the study who had unhealthy cholesterol or triglyceride levels were less likely to be aware of their levels or to be treated for them. Other analyses revealed depression and blood type as potential stroke risk factors in the general population.
- Preventing Stroke Deaths in Older Adults. From 1984 to 1996, the NHLBI supported the Systolic Hypertension in the Elderly Program (SHEP), which studied high blood pressure treatment in adults age 60 and older. The study found that medicines for high blood pressure can decrease the risk of stroke. In a more recent NHLBI-supported study, depression, stress, and a negative outlook on life were linked to a higher chance of dying from stroke in older adults. The findings point to the importance of mental health for brain health in older adults.
Learn about some of the pioneering research contributions we have made over the years that have improved clinical care.
- Predicting when to use blood thinners to prevent stroke. Doctors are better able to recommend short-term treatments to lower the risk of stroke if they can accurately assess their patient’s stroke risk. NHLBI-funded researchers developed a more accurate and reliable stroke prediction model to help physicians decide whether to start blood-thinning treatment for patients with atrial fibrillation. The findings are a result of the Anticoagulation and Risk Factors in Atrial Fibrillation Study (ATRIA) conducted within the NHLBI-supported Cardiovascular Research Network.
- Unveiling new mechanisms in stroke. Investigating the causes of stroke can lead to new approaches for treatment. NHLBI-supported researchers looked at the genes of 500,000 people to identify the first genes tied to risk of stroke. In another NHLBI-funded study, researchers looked at immune cells inside plaques removed from people who had a stroke and had carotid artery disease. The plaques contained a lot of a type of T-cell that can cause inflammation. Another study found that bacteria in the gut may contribute to the formation of cerebral cavernous malformations (CCMs), clusters of dilated, thin-walled blood vessels in the brain that can cause stroke.
- Understanding mental health complications of stroke. NHLBI-supported researchers looked at multiple studies and found that 1 in 4 people who survived a stroke or transient ischemic attack develop symptoms of PTSD within one year. These findings may help doctors and their patients recognize if they have symptoms of PTSD and get treatment.
- Reducing the burden of stroke in sickle cell disease. NHLBI’s legacy of research on sickle cell disease identified the higher risk of stroke faced by children who have sickle cell disease and ways to reduce that risk. Recommendations based on these findings have led to fewer strokes and helped people live longer.
- Highlighting health disparities in stroke. The American Heart Association cited health data from several NHLBI-funded studies—including MESA—in a 2017 scientific statement of health disparities in African Americans. The statement concluded that African Americans have a shorter life expectancy than white Americans, in part due to higher rates of heart disease and stroke. The NHLBI also helped highlight how stroke and other lifestyle diseases contribute to poverty around the world.
- Finding new risk factors for stroke. NHLBI-funded researchers found that people living with HIV had a higher risk of stroke than those who did not have HIV. In addition, studies from the Framingham Heart Study and the Women’s Health Initiative found that people who regularly drank diet sodas (containing artificial sweeteners) were more likely to have a stroke than those who did not. Other research showed that obstructive sleep apnea also raises the risk. These findings point to new approaches to understand and help prevent strokes.
- Discovering one preventive heart procedure is not effective against stroke. Atrial fibrillation raises the risk of blood clots forming in the heart, which can travel to the brain and cause stroke. It was thought that a procedure to close off a small part of the heart from circulation could help prevent blood clots and stroke. However, NHLBI-funded researchers looking at more than 10,000 people found that the procedure, called left atrial appendage closure, did not lower the risk of stroke or stroke deaths.
- Understanding the burden of stroke around the world. Accurately tracking worldwide trends in stroke is a global priority. With the Centers for Disease Control and Prevention and the American Heart Association, the NHLBI contributes data from its major studies for an annual report on U.S. statistics for stroke and transient ischemic attacks. Together with the Bill & Melinda Gates Foundation, we advance research efforts to document and monitor the burden of stroke worldwide.
Advancing research for improved health
In support of our mission, we are committed to advancing stroke research in part through the following ways.
- We perform research. Our Division of Intramural Research, which includes investigators from the Population Sciences Branch and the Vascular Physiology Lab of the Sickle Cell Branch, performs research on stroke.
- We fund research. The research we fund today will help improve our future health. Our Division of Cardiovascular Sciences, which includes the Clinical Applications and Prevention Branch, oversees much of the research on stroke that we fund, helping us to manage other conditions. Search the NIH RePORTer to learn about research the NHLBI is funding on stroke.
- We stimulate high-impact research. Our Trans-Omics for Precision Medicine (TOPMed) program includes participants who have stroke, which may help us understand how genes contribute to differences in disease severity and how patients respond to treatment. The NHLBI Strategic Vision highlights ways we may support research over the next decade.
Learn about exciting research areas the NHLBI is exploring about stroke.
- Expanding treatment options for patients. The NHLBI actively pursues new treatment options for stroke. Exploratory research in animals has shown that a naturally occurring protein, activated protein C, can safely and effectively reduce inflammation. It is also known to prevent blood clots in the brain. Researchers are testing an altered form of the protein for development as a potential new treatment for stroke. It would be the first new treatment for stroke since tissue plasminogen activator (tPA), widely used today.
- Understanding how stroke affects newborns. With the National Institute of Neurological Disorders and Stroke, we fund research on a major cause of cerebral palsy: stroke that occurs before or shortly after birth. This research will help us learn more about these events and develop new ways to detect and treat stroke in newborns.
- Testing models of clot formation and blood flow. We support research to build computer models of the way blood flows through the heart. Researchers think better models can improve how well doctors predict the risk of stroke among patients who have atrial fibrillation and test the effectiveness of treatments. Visit Multiscale Modeling of Clotting Risk in Atrial Fibrillation to learn more.
- Exploring the formation of tangled blood vessel networks. Hereditary hemorrhagic telangiectasia (HHT) is a rare genetic disorder that leads to blood vessel abnormalities known as arteriovenous malformations (AVMs). AVMs can cause hemorrhagic stroke. The NHBLI supports studies in animals to understand how the genetic disease causes AVMs to form and to examine treatments to prevent brain hemorrhages. For more information, visit BMP10 in Cardiovascular Development and Hereditary Hemorrhagic Telangiectasia and Molecular Mechanisms Underlying Arteriovenous Malformations Associated with HHT.
- Targeting inflammation to prevent stroke. The NHLBI is investing in new ways to treat heart and blood vessel diseases by supporting research focused on the role of inflammation. A current NHLBI-funded study, the Cardiovascular Inflammation Reduction Trial (CIRT), is testing methotrexate, a drug that helps reduce inflammation, to determine if it reduces the number of strokes and other complications in people who have multiple coronary blockages or who have experienced a prior heart attack. Visit CIRT for more information.
- Identifying genetic patterns that may indicate stroke risk. Genetics may open up a new understanding of how stroke affects certain populations and lead to tools to reduce disparities in stroke and stroke deaths. An NHLBI-supported study is examining blood samples and data collected for the Jackson Heart Study, REGARDS, and TOPMed to find gene patterns linked to blood clot formation and inflammation in African Americans. Another study using TOPMed data aims to find genes linked to ischemic stroke in women. Findings from these studies could one day lead to better screening and prevention of stroke. Visit Thrombosis Genetics in African Americans and Whole Genome Sequence Analysis of Ischemic Stroke in the Women's Health Initiative for more information.
- Exploring a link between poor sleep and another stroke. We support research to understand how sleep helps keep us in good health and recover from disease and injury. NHLBI-supported researchers are exploring how poor sleep and lack of physical activity affect the risk of having another stroke or transient ischemic attack. In another study, investigators are assessing the impact of sleep apnea on recovery after stroke in the Hispanic community. These findings may reveal a new focus for efforts to improve stroke patients’ general health and help prevent another stroke. Visit Poor Sleep, Sedentary Behavior, and Secondary Cardiovascular Risk in Stroke and TIA Patients and Sleep Apnea after Stroke: Implications for Screening and Treatment for more information.
- Advancing imaging techniques for stroke. The NHLBI supports advances in imaging techniques. This may help doctors find previously unidentified causes of stroke, detect formation of dangerous blood clots, and figure out when plaque is most likely to break open and develop a clot. For example, researchers are exploring new uses for positron emission tomography (PET) and magnetic resonance imaging (MRI). Visit MRI Detection of Carotid Plaques as a Mechanism for Embolic Strokes of Undetermined Source (MRI DECIPHER) and Direct Detection and Characterization of Thrombosis in Vivo for more information.
Participate in NHLBI Clinical Trials
We lead or sponsor many studies on stroke. See if you or someone you know is eligible to participate in ourand .
Did you develop atrial fibrillation after coronary artery bypass graft (CABG) surgery?
Do you or your child have severe sickle cell disease and also know a half-matched bone marrow donor?
Are you an adult who has uncontrolled high blood pressure?
Are you a stroke survivor?
Have you been diagnosed with carotid artery plaque?
Do you have diabetes and a history of heart attack?
After reading our Stroke Health Topic, you may be interested in additional information found in the following resources.
Related Health Topics
- Diabetes (National Institute of Diabetes and Digestive and Kidney Diseases)
- NINDS Transient Ischemic Attack Information Page (National Institute of Neurological Disorders and Stroke [NINDS])
- End of Life (National Institute on Aging)
- Stroke (National Library of Medicine [NLM], MedlinePlus)
- Stroke Information Page (NINDS)
- Stroke Recovery (NLM, MedlinePlus)