Pleurisy (PLUR-ih-se) is a condition in which the pleura is inflamed. The pleura is a membrane that consists of two large, thin layers of tissue. One layer wraps around the outside of your lungs. The other layer lines the inside of your chest cavity.
Between the layers of tissue is a very thin space called the pleural space. Normally this space is filled with a small amount of fluid—about 4 teaspoons full. The fluid helps the two layers of the pleura glide smoothly past each other as you breathe in and out.
Pleurisy occurs if the two layers of the pleura become irritated and inflamed. Instead of gliding smoothly past each other, they rub together every time you breathe in. The rubbing can cause sharp pain.
Many conditions can cause pleurisy, including viral infections.
Air or gas can build up in the pleural space. When this happens, it's called a pneumothorax (noo-mo-THOR-aks). A lung disease or acute lung injury can cause a pneumothorax.
Sometimes the cause of a pneumothorax isn't known.
The most common symptoms of a pneumothorax are sudden pain in one side of the lung and shortness of breath. The air or gas in the pleural space also can put pressure on the lung and cause it to collapse.
A small pneumothorax may go away without treatment. A large pneumothorax may require a procedure to remove air or gas from the pleural space.
A very large pneumothorax can interfere with blood flow through your chest and cause your blood pressure to drop. This is called a tension pneumothorax.
In some cases of pleurisy, excess fluid builds up in the pleural space. This is called a pleural effusion. A lot of extra fluid can push the pleura against your lung until the lung, or part of it, collapses. This can make it hard for you to breathe.
Sometimes the extra fluid gets infected and turns into an abscess. When this happens, it's called an empyema (em-pi-E-ma).
You can develop a pleural effusion even if you don't have pleurisy. For example, pneumonia, (nu-MO-ne-ah), heart failure, cancer, or pulmonary embolism (PULL-mun-ary EM-bo-lizm) can lead to a pleural effusion.
Blood also can build up in the pleural space. This condition is called a hemothorax (he-mo-THOR-aks). An injury to your chest, chest or heart surgery, or lung or pleural cancer can cause a hemothorax.
A hemothorax can put pressure on the lung and cause it to collapse. A hemothorax also can cause shock. In shock, not enough blood and oxygen reach your body's vital organs.
Pleurisy and other pleural disorders can be serious, depending on their causes. If the condition that caused the pleurisy or other pleural disorder isn't too serious and is diagnosed and treated early, you usually can expect a full recovery.
Many conditions can cause pleurisy. Viral infections are likely the most common cause. Other causes of pleurisy include:
Other causes of pleurisy include chest injuries, pancreatitis (an inflamed pancreas), and reactions to some medicines.
Sometimes the cause of pleurisy isn't known.
A lung disease or an acute lung injury can cause a pneumothorax (a buildup of air or gas in the pleural space). Lung diseases that can cause a pneumothorax include COPD (chronic obstructive pulmonary disease), tuberculosis, LAM, and cystic fibrosis.
Surgery or a chest injury also may cause a pneumothorax.
You can develop a pneumothorax without having a recognized lung disease or chest injury. This is called a spontaneous pneumothorax. Smoking increases your risk of spontaneous pneumothorax. Having a family history of the condition also increases your risk.
The most common cause of a pleural effusion (a buildup of fluid in the pleural space) is heart failure. Lung cancer, LAM, pneumonia, tuberculosis, and other lung infections also can lead to a pleural effusion.
Sometimes kidney or liver disease can cause fluid to build up in the pleural space. Asbestosis, sarcoidosis (sar-koy-DO-sis), and reactions to some medicines also can lead to a pleural effusion.
An injury to the chest, chest or heart surgery, or lung or pleural cancer can cause a hemothorax (a buildup of blood in the pleural space).
An infection (for example, pneumonia), tuberculosis, or a spontaneous pneumothorax also can lead to a hemothorax.
The main symptom of pleurisy is sharp or stabbing chest pain. The pain gets worse when you breathe in deeply, cough, or sneeze.
The pain may stay in one place or spread to your shoulders or back. Sometimes the pain becomes a fairly constant dull ache.
Depending on the cause of the pleurisy, you may have other symptoms such as:
The symptoms of a pneumothorax include:
Other symptoms of pneumothorax include flaring of the nostrils; anxiety, stress, and tension; and hypotension (low blood pressure).
A pleural effusion often has no symptoms. However, the disorder may cause shortness of breath or chest discomfort.
The symptoms of a hemothorax often are similar to those of a pneumothorax. They include:
Your doctor will diagnose pleurisy or another pleural disorder based on your medical history, a physical exam, and test results.
Your doctor will want to rule out other causes of your symptoms. He or she also will want to find the underlying cause of the pleurisy or other pleural disorder so it can be treated.
Your doctor may ask detailed questions about your medical history. He or she likely will ask you to describe any pain, especially:
Your doctor also may ask whether you have other symptoms, such as shortness of breath, coughing, or palpitations. Palpitations are feelings that your heart is skipping a beat, fluttering, or beating too hard or fast.
Your doctor also may ask whether you've ever:
Your doctor also may ask about medicines you take or have taken. Reactions to some medicines can cause pleurisy or other pleural disorders.
Your doctor will listen to your breathing with a stethoscope to find out whether your lungs are making any abnormal sounds.
If you have pleurisy, the inflamed layers of the pleura make a rough, scratchy sound as they rub against each other when you breathe. Doctors call this a pleural friction rub. If your doctor hears the friction rub, he or she will know that you have pleurisy.
If you have a pleural effusion, fluid buildup in the pleural space will prevent a friction rub. But if you have a lot of fluid, your doctor may hear a dull sound when he or she taps on your chest. Or, he or she may have trouble hearing any breathing sounds.
Muffled or dull breathing sounds also can be a sign of a pneumothorax (a buildup of air or gas in the pleural space).
Depending on the results of your physical exam, your doctor may recommend tests.
A chest x ray is a painless test that creates a picture of the structures in your chest, such as your heart, lungs, and blood vessels. This test may show air or fluid in the pleural space.
A chest x ray also may show what's causing a pleural disorder—for example, pneumonia, a fractured rib, or a lung tumor.
Sometimes a chest x ray is taken while you lie on your side. This position can show fluid that didn't appear on an x ray taken while you were standing.
A chest computed tomography (to-MOG-rah-fee) scan, or chest CT scan, is a painless test that creates precise pictures of the structures in your chest.
This test provides a computer-generated picture of your lungs that can show pockets of fluid. A chest CT scan also may show signs of pneumonia, a lung abscess, a tumor, or other possible causes of pleural disorders.
This test uses sound waves to create pictures of your lungs. An ultrasound may show where fluid is located in your chest. The test also can show some tumors.
A chest magnetic resonance imaging scan, or chest MRI, uses radio waves, magnets, and a computer to created detailed pictures of the structures in your chest. This test can show pleural effusions and tumors.
This test also is called a magnetic resonance (MR) scan or a nuclear magnetic resonance (NMR) scan.
Blood tests can show whether you have an illness that increases your risk of pleurisy or another pleural disorder. Such illnesses include bacterial or viral infections, pneumonia, pancreatitis (an inflamed pancreas), kidney disease, or lupus.
For this test, a blood sample is taken from an artery, usually in your wrist. The blood's oxygen and carbon dioxide levels are checked. This test shows how well your lungs are taking in oxygen.
Once your doctor knows whether fluid has built up in the pleural space and where it is, he or she can remove a sample for testing. This is done using a procedure called thoracentesis (THOR-ah-sen-TE-sis).
During the procedure, your doctor inserts a thin needle or plastic tube into the pleural space and draws out the excess fluid. After the fluid is removed from your chest, it's sent for testing.
The risks of thoracentesis—such as pain, bleeding, and infection—usually are minor. They get better on their own, or they're easily treated. Your doctor may do a chest x ray after the procedure to check for complications.
The fluid removed during thoracentesis is examined under a microscope. It's checked for signs of infection, cancer, or other conditions that can cause fluid or blood to build up in the pleural space.
Your doctor may suspect that tuberculosis or cancer has caused fluid to build up in your pleural space. If so, he or she may want to look at a small piece of the pleura under a microscope.
To take a tissue sample, your doctor may do one of the following procedures:
Pleurisy and other pleural disorders are treated with procedures, medicines, and other methods. The goals of treatment include:
To relieve pleurisy symptoms, your doctor may recommend:
Your doctor may recommend removing fluid, air, or blood from your pleural space to prevent a lung collapse.
The procedures used to drain fluid, air, or blood from the pleural space are similar.
Sometimes the fluid in the pleural space contains thick pus or blood clots. It may form a hard skin or peel, which makes the fluid harder to drain. To help break up the pus or blood clots, your doctor may use a chest tube to deliver medicines called fibrinolytics to the pleural space. If the fluid still won't drain, you may need surgery.
If you have a small, persistent air leak into the pleural space, your doctor may attach a one-way valve to the chest tube. The valve allows air to exit the pleural space, but not reenter. Using this type of valve may allow you to continue your treatment from home.
The fluid sample that was removed during thoracentesis will be checked under a microscope. This can tell your doctor what's causing the fluid buildup, and he or she can decide the best way to treat it.
If the fluid is infected, treatment will involve antibiotics and drainage. If you have tuberculosis or a fungal infection, treatment will involve long-term use of antibiotics or antifungal medicines.
If tumors in the pleura are causing fluid buildup, the fluid may quickly build up again after it's drained. Sometimes antitumor medicines will prevent further fluid buildup. If they don't, your doctor may seal the pleural space. Sealing the pleural space is called pleurodesis (plur-OD-eh-sis).
For this procedure, your doctor will drain all of the fluid out of your chest through a chest tube. Then he or she will push a substance through the chest tube into the pleural space. The substance will irritate the surface of the pleura. This will cause the two layers of the pleura to stick together, preventing more fluid from building up.
Chemotherapy or radiation treatment also may be used to reduce the size of the tumors.
If heart failure is causing fluid buildup, treatment usually includes diuretics (medicines that help reduce fluid buildup) and other medicines.
The National Heart, Lung, and Blood Institute (NHLBI) is strongly committed to supporting research aimed at preventing and treating heart, lung, and blood diseases and conditions and sleep disorders.
NHLBI-supported research has led to many advances in medical knowledge and care. Often, these advances depend on the willingness of volunteers to take part in clinical trials.
Clinical trials test new ways to prevent, diagnose, or treat various diseases and conditions. For example, new treatments for a disease or condition (such as medicines, medical devices, surgeries, or procedures) are tested in volunteers who have the illness. Testing shows whether a treatment is safe and effective in humans before it is made available for widespread use.
By taking part in a clinical trial, you can gain access to new treatments before they're widely available. You also will have the support of a team of health care providers, who will likely monitor your health closely. Even if you don't directly benefit from the results of a clinical trial, the information gathered can help others and add to scientific knowledge.
If you volunteer for a clinical trial, the research will be explained to you in detail. You'll learn about treatments and tests you may receive, and the benefits and risks they may pose. You'll also be given a chance to ask questions about the research. This process is called informed consent.
If you agree to take part in the trial, you'll be asked to sign an informed consent form. This form is not a contract. You have the right to withdraw from a study at any time, for any reason. Also, you have the right to learn about new risks or findings that emerge during the trial.
For more information about clinical trials related to pleurisy and other pleural disorders, talk with your doctor. You also can visit the following Web sites to learn more about clinical research and to search for clinical trials:
For more information about clinical trials for children, visit the NHLBI's Children and Clinical Studies Web page.
The NHLBI updates Health Topics articles on a biennial cycle based on a thorough review of research findings and new literature. The articles also are updated as needed if important new research is published. The date on each Health Topics article reflects when the content was originally posted or last revised.