Pleural effusion

[Dorothey Allen]

Pleural effusion is the abnormal accumulation of fluid in the pleural space (the area between the two layers of the thin membrane that covers the lungs).

Fluid can accumulate in the pleural space as a result of a large number of disorders, including infections, tumors, injuries, heart, kidney, or liver failure, blood clots in the lung blood vessels (pulmonary emboli), and drugs.
Symptoms may include difficulty breathing and chest pain particularly when breathing and coughing.
Diagnosis is by chest x-rays, laboratory testing of the fluid, and often computed tomography angiography.
Large amounts of fluid are drained with a tube inserted into the chest.

(See also Overview of Pleural and Mediastinal Disorders.)
Normally, only a thin layer of fluid separates the two layers of the pleura. An excessive amount of fluid may accumulate for many reasons, including heart failure, cirrhosis, pneumonia, and cancer.
A large number of disorders may cause pleural effusion. Some of the more common causes (listed as most common to least common) include

Heart failure
Tumors
Pneumonia
Pulmonary embolus
Surgery, such as recent coronary artery bypass surgery
Injury to the chest
Cirrhosis
Kidney failure
Systemic lupus erythematosus (lupus)
Pancreatitis
Rheumatoid arthritis
Tuberculosis
Nephrotic syndrome (protein in the urine and high blood pressure)
Peritoneal dialysis
Drugs such as hydralazine , procainamide , isoniazid , phenytoin , chlorpromazine , methysergide, interleukin-2, nitrofurantoin , bromocriptine , dantrolene , and procarbazine