Between the layer of the pleura that wraps around the lungs and the layer that lines the chest cavity is a very thin space. This is called the pleural space or pleural cavity. Normally it's 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 the lungs breathe air in and out.
Pleurisy occurs when the two layers of the pleura become red and inflamed. Then they rub against each other every time the lungs expand to breathe in air. This can cause sharp pain with breathing.
Infections like pneumonia are the most common cause of swelling, or inflammation, of the pleura and pleurisy.
Many different conditions can cause pleurisy. Viral infection is the most common cause. Other conditions that can cause pleurisy are:
Other causes of pleurisy include:
In some cases, doctors can't find the cause of the pleurisy.
Signs and symptoms
The main symptom of pleurisy is a sharp or stabbing pain in your chest that gets worse when you breathe in deeply or cough or sneeze.
The pain may stay in one place or it may spread to your shoulder or back. Sometimes it becomes a fairly constant dull ache.
Depending on what's causing the pleurisy, you may have other symptoms, such as:
Your doctor will find out if you have pleurisy or another pleural disorder by taking a detailed medical history and doing a physical exam and several tests. The purpose is to:
Your doctor will ask you for a detailed medical history. He or she is likely to ask you to describe the pain, especially:
Your doctor will probably also want to know about any other symptoms that you may have, like shortness of breath, cough, or palpitations (a feeling that your heart has skipped a beat or is beating too hard).
Other things your doctor is likely to ask about include whether you've ever:
Your doctor will listen to your breathing with a stethoscope to find out whether your lungs are making any strange sounds.
When 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 has built up in the pleural space and pushed the two layers of the pleura apart so that they don't produce 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 the doctor may have trouble hearing any breathing sounds.
Reduced breathing sounds also can be a sign of pneumothorax.
Depending on the results of your physical exam, your doctor may recommend other diagnostic tests.
A chest X-ray takes a picture of your heart and lungs. It may show air or fluid in the pleural space. It also may show what's causing the condition – for example, pneumonia, a fractured rib, or a lung tumor.
Sometimes an X-ray is taken while you lie on the side where the pain is. This may show fluid that didn't appear on the standard X-ray taken while you were standing.
Computed tomography (CT) scan
This test uses sound waves to create pictures of your lungs. It may show where fluid is located in your chest. It also can show some tumors.
Magnetic resonance (MR) scan
This test also is called nuclear magnetic resonance (NMR) scanning or magnetic resonance imaging (MRI). It uses powerful magnets and radio waves to show pleural effusions and tumors.
Blood tests can show whether you have a bacterial or viral infection, pneumonia, rheumatic fever, a pulmonary embolism, or lupus.
Arterial blood gas tests
In this test, a small amount of blood is taken from an artery in your wrist. It's then checked for oxygen and carbon dioxide levels. 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 test is called thoracentesis. The doctor inserts a small needle or a thin, hollow, plastic tube through the ribs in the back of your chest into your chest wall and draws fluid out of your chest.
Thoracentesis usually doesn't take long. Most of the time, it can be done in your doctor's office or at your hospital bed. Many doctors use ultrasound to guide the needle to the fluid that's trapped in small pockets around your lungs.
Thoracentesis usually doesn't cause serious complications, but your doctor may do a chest X-ray after the procedure to be sure. Most of the complications are minor and will get better on their own, or they're easily treated.
Possible complications of thoracentesis include:
Doctors look at the fluid removed by thoracentesis under a microscope. They look at the chemicals in it and its color, texture, and clearness for signs of infection, cancer, or other conditions that may be causing the buildup of fluid or blood in the pleural space.
If your doctor thinks that tuberculosis or cancer may have caused the fluid buildup, he or she may want to look at a small piece of the pleura under a microscope.
To take a tissue sample, the doctor may:
The goals of treatment for patients with pulmonary arterial hypertension (PAH) are to:
Remove fluid, air, or blood from the pleural space
If large amounts of fluid, air, or blood aren't removed from the pleural space, they may put pressure on your lung and cause it to collapse.
The procedures used to drain fluid, air, or blood from the pleural space are similar.
For relief of pleurisy symptoms, your doctor may recommend:
Treating the underlying condition
Looking at the fluid under a microscope can often tell the doctor what's causing the fluid buildup. Then treatment of the underlying condition can begin.
If the fluid is infected, treatment involves antibiotics and draining the fluid. If the infection is tuberculosis or from a fungus, treatment involves long-term use of antibiotics or antifungal medicines.
If the fluid is caused by tumors of the pleura, it may build up again quickly after it's drained. Sometimes antitumor medicines will prevent further fluid buildup. If they don't, the doctor may seal the pleural space. This is called pleurodesis.
In pleurodesis, the doctor drains all the fluid out of the chest through a chest tube. Then he or she pushes a substance through the chest tube into the pleural space. This substance irritates the surface of the pleura. This causes the two layers of the pleura to squeeze shut so there is no room for more fluid to build up.
Chemotherapy or radiation treatment also may be used to reduce the size of the tumors.
If congestive heart failure is causing the fluid buildup, treatment usually includes diuretics and other medicines.