Thoracentesis is a procedure in which a doctor uses a needle and catheter to remove excess fluid from the space between your lungs and the wall of your chest, known as the pleural space. You might ...

Doctors use synovial fluid analysis, or synovial joint analysis, to help diagnose the cause of joint pain and to rule out infection. Common causes of joint pain include rheumatoid arthritis (RA), ...

Paracentesis is a medical procedure that doctors perform to drain fluid from a person’s abdominal cavity. It is sometimes called an abdominal tap. Doctors refer to this buildup of fluid as ascites, ...