Fluid around the heart, also known as pericardial effusion, results from inflammation of the pericardium, which is the sac-like double-layered structure that surrounds the heart, according to Mayo Clinic. Inflammation occurs as a response to injury, disease or inflammatory disorders that affect the pericardium, such as fungal, bacterial, parasitic or viral infections. As of 2015, it is not clear why some diseases cause the condition, and its cause is sometimes unknown.
Idiopathic pericarditis, which is inflammation of the pericardium due to non-specific causes, and Dressler’s syndrome, which is inflammation of the pericardium after a heart attack or heart surgery, also cause pericardial effusion, notes Mayo Clinic. Rheumatoid arthritis, lupus, hypothyroidism and kidney failure also cause the condition.
Certain cancers and the spread of cancer can lead to pericardial effusion, explains Mayo Clinic. Cancer of the heart or the pericardium and the metastasis of lung or breast cancers, leukemia, melanoma or non-Hodgkin lymphoma may result in fluid building up in the pericardial space. Cancer treatments, including radiation therapy, if the heart is within the radiation’s field of reach, and certain drugs used during chemotherapy, are additional causes.
Some drugs may lead to fluid build-up and pericardial effusion, notes Mayo Clinic. For example, certain medications used for treating epileptic seizures, tuberculosis and high blood pressure are associated with the condition.