Paracentesis is a procedure during which fluid from the abdomen is removed through a needle. There are two reasons to take fluid out of the abdomen. One is to analyze it. The other is to relieve pressure. Liquid that accumulates in the abdomen is called ascites. Ascites seeps out of organs for several reasons related either to disease in the organ or fluid pressures that are changing. There are several generally accepted indications for abdominal paracentesis. In addition to helping to clarify the cause of ascites and evaluating for infection, it can identify unexpected diagnoses, such as chylous, hemorrhagic, eosinophilic ascites, and tuberculous peritonitis. In one report, approximately 5 percent of patients with cirrhosis and bacterial infection of their ascitic fluid had a surgically-treatable cause such as a perforated viscus or abscess.