What is the pericardium?

The pericardium is a thin sac that surrounds your heart. It protects and lubricates your heart and keeps it in place within your chest.

Problems can occur when the pericardium becomes enflamed or fills with fluid. The swelling can damage your heart and affect its function.

The pericardium has a few important roles:

  • It keeps your heart fixed in place within your chest cavity.
  • It prevents your heart from stretching too much and overfilling with blood.
  • It lubricates your heart to prevent friction with the tissues around it as it beats.
  • It protects your heart from any infections that might spread from nearby organs like the lungs.

The pericardium has two layers:

  • Fibrous pericardium is the outer layer. It’s made from thick connective tissue and is attached to your diaphragm. It holds your heart in place in the chest cavity and protects from infections.
  • Serous pericardium is the inner layer. It’s further divided into two more layers: the visceral and parietal layers. The serous pericardium helps to lubricate your heart.

In between these two layers is the fluid-filled pericardial cavity. It lubricates the heart and protects it from injury.

Pericardial effusion is the buildup of too much fluid between the pericardium and your heart. This can happen from damage or disease in the pericardium. Fluid can also build up if there’s bleeding in your pericardium after an injury.

Possible causes of pericardial effusion include:

  • diseases that cause inflammation, such as lupus or rheumatoid arthritis
  • severe underactive thyroid (hypothyroidism)
  • infections
  • recent heart surgery
  • cancer that has spread to your pericardium
  • kidney failure

Symptoms of pericardial effusion include:

  • chest pressure or pain
  • shortness of breath
  • difficulty breathing when you lie down
  • nausea
  • a feeling of fullness in your chest
  • trouble swallowing

The excess fluid from pericardial effusion can cause intense pressure on your heart and damage it.

A pericardial cyst is a noncancerous, fluid-filled growth in the pericardium. This type of cyst is very rare, affecting only 1 in 100,000 people.

Most people who have pericardial cysts are born with them, but they often aren’t diagnosed until they reach their 20s or 30s.

Pericardial cysts are usually found during a chest X-ray that’s done for another reason since these cysts don’t cause symptoms on their own.

Symptoms may only appear when the cyst presses on nearby organs or structures, and can include:

  • pain in your right shoulder that radiates to your left shoulder
  • shortness of breath
  • rapid, strong heart rate (palpitations)
  • a feeling of fullness in your chest

Pericardial cysts aren’t dangerous themselves. However, if they press on your lungs or other structures in your chest, they can cause complications like inflammation or severe bleeding. Rarely, a pericardial cyst can lead to heart failure.

A few other conditions and complications can also affect the pericardium.


Pericarditis is swelling of the pericardium. Possible causes include:

  • infection with a virus, bacteria, or fungus
  • autoimmune disorders such as lupus, rheumatoid arthritis, and scleroderma
  • heart attack
  • heart surgery
  • injuries, such as from a car accident
  • kidney failure
  • tuberculosis
  • medications such as phenytoin (Dilantin), warfarin (Coumadin), and procainamide

Acute pericarditis starts suddenly and lasts only a few weeks. Chronic pericarditis develops more slowly and can last longer.

Usually pericarditis is mild and heals over time. Sometimes it will improve with plenty of rest. More severe pericarditis may need to be treated with medication or surgery to prevent it from damaging your heart.

Cardiac tamponade

Cardiac tamponade is a condition that’s caused by a buildup of fluid, blood, gas, or a tumor in your pericardial cavity. This buildup places pressure on your heart, which prevents it from filling and emptying properly.

Cardiac tamponade is not the same as pericardial effusion, though it can be a complication of fluid buildup from pericardial effusion.

One sign of cardiac tamponade is a large drop in blood pressure. Cardiac tamponade is a medical emergency. It can be life threatening if it isn’t treated quickly.

The pericardium anchors and protects your heart and allows it to move easily within your chest. When fluid or other substances build up in the pericardium, they can put pressure on your heart and affect its ability to pump blood.

Some conditions that affect the pericardium aren’t serious and will improve on their own. Others can damage your heart and are considered medical emergencies.

If you have symptoms such as chest pain, shortness of breath, and a feeling of fullness in your chest, see your doctor right away. They can perform tests to find the cause of the problem and advise you about treatments to prevent heart damage.