Paracentesis is a way of removing excess fluid from the abdomen using a needle or catheter.
Fluid called ascites can build up inside your abdomen due to cirrhosis of the liver, portal hypertension, infection, cancer, or other reasons. Paracentesis allows a doctor to remove some of the fluid so that they can see what's causing your condition. Removing some of the fluid can also help relieve symptoms.
Your doctor will use an ultrasound to see where the fluid is, then insert a needle into the correct location. A catheter will be placed to help drain the fluid.