Paracentesis is a procedure that removes fluid buildup inside your abdomen, called ascites. Your healthcare provider may remove a small amount of fluid to test for what’s causing the buildup. Or, you may need paracentesis to relieve symptoms of ascites, like pressure and pain in your abdomen.


Comparison of an abdomen without ascites and an abdomen with ascites that’s being treated with paracentesis
A provider may perform a paracentesis to drain ascites or collect a fluid sample to help diagnose what's causing the fluid buildup.

What is paracentesis?

Paracentesis is a procedure that drains excess fluid called ascites from your abdomen. Ascites occur when fluid collects in a membrane called your peritoneum. Your peritoneum covers your abdominal organs, including your stomach, liver, kidney and parts of your intestines. It consists of two layers. Ascites form when fluid builds up between the two layers, a place called your peritoneal cavity.

During paracentesis, a healthcare provider uses a needle and a plastic tube called a catheter to drain the ascites. Draining the fluid can relieve unpleasant symptoms like pressure in your abdomen. Sometimes healthcare providers drain the fluid to run tests on it. Test results show what’s causing ascites.

When is a paracentesis done?

Healthcare providers perform paracentesis to diagnose conditions that cause ascites. Paracentesis is also a treatment. Your provider may recommend paracentesis if more conservative treatments for ascites, like water pills (diuretics) or switching to a low-sodium diet, haven’t helped.

Diagnostic paracentesis

Paracentesis can help your provider diagnose common causes of ascites, including:

  • Cirrhosis of the liver: This is the most common cause of ascites.
  • Portal hypertension: This is high blood pressure in the main vein in your liver. It’s common in people with cirrhosis of the liver.
  • Infection: The fluid can become infected and cause inflammation (peritonitis).
  • Cancer: The most common types that cause ascites are ovarian cancer, uterine cancer, cervical cancer, colon cancer, stomach cancer, pancreatic cancer and liver cancer.
  • Organ failure: Liver failure and heart failure can cause ascites.
Therapeutic paracentesis

Therapeutic paracentesis can relieve symptoms of ascites. Common symptoms include:


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Procedure Details

How should I prepare for paracentesis?

Your healthcare provider will explain the procedure and ensure you’re prepared. They’ll:

  • Ensure you’re a good candidate for paracentesis. Your provider will review your medical history, including previous surgeries, allergies and your response to anesthesia. They’ll determine whether you’re pregnant. You can still get paracentesis during pregnancy. Your provider will take care to keep you and the fetus safe.
  • Advise you on medicines and supplements to take. You may need to stop taking blood thinners, like aspirin or warfarin (Coumadin®), vitamins and supplements. You may need to change your medicines if you take nonsteroidal anti-inflammatory drugs (NSAIDs) or certain diabetes medications. Follow your provider’s instructions.
  • Advise you on fasting. Before your procedure, you may need to stop drinking liquids or eating certain foods. Your provider will advise you on adjusting your eating and drinking so you’re prepared.

What happens during this procedure?

You can get paracentesis in your provider’s office or at a hospital. You may need to pee beforehand so your bladder is empty for the procedure.

Once you’re ready, a healthcare provider will:

  1. Position you. Chances are, you’ll be on your back. The bed may be completely flat, or it may be slightly raised to lift your head.
  2. Clean and numb the area where the needle will go. You’ll get a small injection of medicine that prevents you from feeling any pain. You may feel a quick prick when the needle goes in.
  3. Insert the needle and catheter. Your provider will insert the needle in the numbed area, above the ascites. Many providers use an ultrasound while inserting the needle. Ultrasounds show fluid buildup in your body (like ascites), so your provider knows exactly where the needle should go. They’ll place a plastic catheter tube into the site to help the fluid drain.
  4. Drain the ascites. They may use a syringe or a vacuum-powered container to collect the fluid. They’re more likely to use a vacuum container with suction power if they’re draining several liters of fluid. This makes the process go faster.
  5. Remove the needle and bandage the site. They’ll remove the needle and apply pressure to the site to stop bleeding. They’ll bandage the area.

If ascites frequently return after paracentesis, your provider may place a tube called a tunneled peritoneal drainage catheter into the drainage site. You’ll wear this tube long-term, so you won’t have to keep returning for paracentesis. Part of the tube goes inside your abdomen, and the other side goes outside. The outside part attaches to a bottle that continually collects fluid. You’ll drain the bottle at home.

Your healthcare provider will advise you on whether this is a good option.

How long does paracentesis take?

Paracentesis takes from 20 to 45 minutes. Timing depends on how much fluid is removed.

How much fluid can paracentesis remove?

For diagnostic paracentesis, your healthcare provider will remove enough fluid to perform all the necessary tests. This is usually about 25 milliliters (ml).

For therapeutic paracentesis, the amount of fluid depends on how much excess fluid you have and whether you have a history of fluid returning. Often, removing 5 liters is enough to relieve abdominal pressure from ascites. Your provider may remove more fluid if your ascites often return (recur).

How painful is paracentesis?

You may feel a brief sting when the numbing needle goes in. You may also feel pressure or discomfort during the draining, but it shouldn’t feel painful.

Still, let your provider know if you feel uncomfortable or light-headed during the procedure. This is more likely to happen if your provider removes large amounts of fluid. They can give you pain medicines that can help.


What happens after paracentesis?

Your care team will monitor your vital signs for about an hour afterward. While you’re recovering, you may notice small amounts of clear fluid seeping from the bandaged site, but don’t be alarmed. This is normal.

What tests are performed on the fluid sample?

If the procedure is diagnostic, your provider will send the fluid sample to a lab for peritoneal fluid analysis. The analysis includes a series of tests that may include any of the following:

Tests may also check your levels of:

  • Albumin.
  • Alkaline phosphatase.
  • Amylase.
  • Glucose.
  • LDH.
  • Protein.

Knowing these levels can help your healthcare provider determine if your ascites likely result from cancer, an infection, an injury to an organ (like your bowel), organ damage (like heart failure) or other common causes.

Risks / Benefits

What are the benefits of paracentesis?

Paracentesis can relieve symptoms of ascites and help your healthcare provider determine what’s causing fluid to build up.

Paracentesis can save your life, depending on your circumstances. Studies have shown that people with ascites related to cirrhosis who are admitted to the hospital live longer if they have paracentesis. People with bacterial peritonitis (a common infection associated with ascites) who have paracentesis receive life-saving antibiotics sooner than they would have had they not had the procedure.

Does fluid come back after paracentesis?

The fluid does return for some people. Depending on your condition, you may only need paracentesis once to get rid of the ascites. Other people have to return as often as every few weeks.

Your healthcare provider can advise you on how often you’ll need paracentesis based on your condition.


What are the risks or complications of this procedure?

Complications with paracentesis are rare, but they can happen. Complications include:

  • An infection.
  • Ongoing fluid leakage at the wound site (a small amount of leakage is normal).
  • Needle piercing your bowel, bladder or a blood vessel (extremely rare).
  • Internal bleeding or a blood clot that forms beneath your skin (hematoma).
  • Low blood pressure.

Recovery and Outlook

What is the recovery time?

Resting the first 24 hours after your procedure is a good idea. It may take a day or two for small amounts of fluid to stop seeping from the drainage site. But your body should recover quickly.

Follow your provider’s guidance on when it’s safe to resume normal activities based on your lifestyle.

How do I care for myself at home?

Your healthcare provider will instruct you on caring for the wound. You may also need to adjust what you eat and drink. They’ll advise you on:

  • Wound care. Taking steps to prevent infection while caring for your wound is important. Wash your hands with soap and water for at least 20 seconds before changing your wound dressing, or use hand sanitizer. Contact your provider if you see signs of infection, like redness or swelling at the drainage site.
  • Food. You may need to work with a dietitian to get on a low-sodium diet if you’re not on one already. Too much sodium causes you to retain fluid.
  • Drink. If you’re not already doing so, you may need to take water pills. They help flush excess salt and water out of your body so you don’t develop ascites.
  • Hygiene. You may need to avoid baths or even showers until your wound heals. Getting the wound wet puts you at risk of infection. You may need to take sponge baths instead.

When To Call the Doctor

When should I call my healthcare provider?

Contact your healthcare provider if you notice any signs of a complication, including bleeding from the site or an infection. Signs of an infection include:

  • Fever and chills.
  • Tenderness or redness at the site.
  • Foul-smelling drainage or pus.

Visit the ER if you have:

  • Chest pain.
  • Shortness of breath.
  • Light-headedness.
  • Severe pain or swelling in your abdomen.

A note from Cleveland Clinic

Paracentesis is a low-risk procedure that can help your healthcare provider diagnose what’s causing fluid buildup in your abdomen. It can also help relieve symptoms if you’re living with a condition causing ascites. Paracentesis may be a one-time procedure, depending on your condition, or you may need it frequently. Your provider may need to remove a small amount of fluid if they’re trying to diagnose a condition but a larger amount if you have recurring ascites. Ask about what factors will shape your experience before going in for paracentesis so you know what to expect.

Medically Reviewed

Last reviewed on 11/21/2023.

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