Thoracentesis is a procedure used to remove fluid or air from the pleural space, the area between the thin layers of tissue that line the lungs and chest wall. This procedure is used to diagnose and treat various conditions in which fluid or air accumulates in the chest cavity, such as congestion in the lungs, blood clots in the lungs, or fluid accumulation due to an infection or tumor.


Prior to a thoracentesis, your doctor will perform an assessment and physical examination. He or she will ask about your medical history and medications you are taking. You may be asked to undergo other tests (e.g. chest X-ray or ultrasound) to make sure the procedure is safe for you. Tell your doctor if you are on any blood thinners or have a history of bleeding problems.


During the thoracentesis, you will lie on your side on an examination table.Your doctor will clean the area of the chest wall and inject a local anesthetic. After the area is numb, your doctor will insert a long, thin needle through the skin between the ribs and into the pleural space. This needle will be connected to a syringe to collect the fluid.Once the fluid has been collected, the needle will be removed. The puncture site may then be covered with a bandage.


  • Closed thoracentesis - A long, thin needle is inserted into the chest, often between the ribs, and a syringe is used to collect fluid.
  • Open thoracentesis - A larger incision is made in the chest wall and a chest tube is inserted into the chest cavity.


Thoracentesis is generally a safe procedure, but there are certain risks associated with it. These include: bleeding, infection, pneumothorax (collapsed lung), and hemothorax (collection of blood in the pleural space). Rarely, it can lead to injury to the lungs, blood vessels, or other organs. Your doctor will discuss these risks with you prior to the procedure.

Why is Thoracentesis Performed?

Thoracentesis is performed for both diagnostic and therapeutic purposes. It can be used to collect fluid for analysis to diagnose the cause of a pleural effusion. It can also be used to relieve shortness of breath associated with a pleural effusion, by removing excess fluid from the chest cavity.

When is Thoracentesis Necessary?

Thoracentesis is usually recommended when there is a build-up of fluid or air in the chest cavity. This can be caused by a variety of conditions, including pneumonia, cancer, congestive heart failure, and cirrhosis. It can also be used to diagnose or treat a condition known as spontaneous pneumothorax (collapsed lung).