Thoracentesis: Procedure, Risks, Recovery and What to Expect
Updated: 6 days ago
Written and medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026 · How we review
Quick Answer: What is thoracentesis?
Thoracentesis is a procedure in which a provider uses a needle to remove fluid from the pleural space between the lungs and the chest wall. It helps find the cause of a pleural effusion and relieves pressure that makes breathing hard. It is usually done as an outpatient procedure with local numbing and imaging guidance. [1]
What the research says
Ultrasound guidance may make the procedure safer. A meta-analysis of 3 randomized trials (417 patients) found ultrasound-guided thoracentesis succeeded in 96.5% of patients versus 87.9% with the traditional landmark method; collapsed lung occurred in 1 of 99 ultrasound patients versus 20 of 113 landmark patients. (Lakkadghatwala et al., American Journal of Emergency Medicine, 2025) [2]
Serious bleeding is rare, even with clotting problems. A review of 18 studies (5,134 procedures) in people with uncorrected clotting problems or on blood-thinning drugs found a pooled major bleeding and death rate of 0% (95% CI 0%–1%). (Fong et al., Chest, 2021) [3]
Routine pressure monitoring adds little for comfort. In a randomized trial of 124 people having large-volume drainage, measuring chest pressure did not reduce chest discomfort; 6 of 62 people (10%) without monitoring had a symptom-free collapsed lung versus none with monitoring, and no serious complications occurred in either group. (Lentz et al., Lancet Respiratory Medicine, 2019) [4]
Key takeaways
Thoracentesis, also called a pleural tap, drains fluid that has built up around the lungs. [1]
It has two jobs: finding out why the fluid built up, and making breathing easier. [1]
The skin is numbed with a local anesthetic, and imaging helps guide the needle. [1]
Soreness and a short-lived cough are common; serious problems are uncommon. [1]
Most people go home the same day and return to work or school within a few days. [1]
Why is thoracentesis done?
Thoracentesis is done to diagnose the cause of a pleural effusion and to relieve the pressure it puts on the lungs. A pleural effusion is extra fluid in the pleural space, the thin gap between the lungs and the chest wall. [1]
When fluid collects there, it presses on the lung and can make breathing hard. Draining it can bring quick relief. [1]
The fluid sample also goes to a lab. Test results help your care team understand what caused the buildup, which guides the next step in treatment. [1]
More than 170,000 people in the United States have a thoracentesis each year. [1]
What conditions cause the fluid that thoracentesis removes?
Heart failure is one of the most common causes of the pleural effusion that thoracentesis removes. Many other conditions can also lead to fluid around the lungs. [1]
Body system | Conditions that can cause pleural effusion |
Heart and blood vessels | |
Lungs and infection | |
Cancer | Lung cancer and other cancers |
Immune system | Autoimmune diseases such as lupus |
Digestive organs | Pancreatitis, liver disease such as cirrhosis |
Kidneys | Kidney disease |
Sources: [1]
Who performs a thoracentesis?
A thoracentesis is performed by doctors trained in the procedure, most often pulmonologists, internists, intensive care doctors, or thoracic and trauma surgeons. [1]
How do you prepare for a thoracentesis?
You prepare for a thoracentesis by talking through your health history and medicines with your provider before the day of the procedure. Your provider will explain what will happen and answer your questions. [1]
Tell your provider about:
All medicines and herbal supplements, especially blood thinners and antiplatelet drugs. You may be asked to pause some of them, but only stop a medicine if your provider tells you to.
Heart rhythm problems or a history of blood clots.
Past heart valve surgery.
Pregnancy, or the chance you could be pregnant.
Allergies, including to latex, adhesives, skin cleaners or anesthesia.
Also plan to:
Arrange a ride home.
Wear loose, comfortable clothing.
Sources: [1]
What happens during a thoracentesis?
During a thoracentesis, a provider numbs the skin on your back and inserts a needle between the ribs to drain fluid from the pleural space. The steps usually follow this order: [1]
Finding the fluid. Imaging, such as ultrasound or a CT scan, shows where the fluid is.
Monitoring. Your care team monitors you throughout the procedure, and you may get extra oxygen.
Positioning. You sit leaning forward or lie on your side.
Cleaning and numbing. Your back is cleaned, and a local anesthetic numbs the area.
Draining. The needle goes in between two ribs, sometimes guided by a handheld ultrasound, and fluid is removed.
Testing. The fluid is sent to a lab.
Checking the lung. Follow-up imaging confirms that your lung has expanded.
Does thoracentesis hurt?
Thoracentesis should not be painful, because the area is numbed first. If you feel significant pain during the procedure, your provider will stop. [1]
Once the numbing wears off, the area may feel sore. This soreness is the most common side effect. [1]
What are the benefits of thoracentesis?
The main benefits of thoracentesis are that it is a low-risk way to find the cause of fluid buildup and that it relieves pressure that makes breathing hard. [1]
It is also usually an outpatient procedure, so most people go home the same day. [1]
What are the risks of thoracentesis?
The most common side effect of thoracentesis is soreness after the numbing wears off, and coughing for up to an hour afterward is normal. Serious complications are less common. [1]
How often | Risk or side effect |
Common | Soreness at the needle site |
Common, expected | Coughing for up to an hour |
Less common | Bleeding |
Less common | Infection |
Less common | Collapsed lung (pneumothorax) |
Less common | Fluid buildup in the lungs (pulmonary edema) |
Possible | Fluid coming back, which may need repeat procedures |
Sources: [1]
Some people need repeat procedures, sometimes as often as every few days. Providers limit how often they repeat thoracentesis to lower the chance of complications. [1]
Research also supports two safety points. Ultrasound guidance trended toward higher success and fewer collapsed lungs than the older landmark method in a small pooled analysis. [2] And in carefully selected people with clotting problems, major bleeding is uncommon. [3]
What is recovery like after thoracentesis?
Recovery after thoracentesis is usually quick, and most people return to work or school within a few days. [1]
When | What to expect or do |
First hour | Some coughing is normal |
After the numbing wears off | Soreness at the site |
After 24 hours | The bandage can usually come off |
First few days | Avoid strenuous activity such as running, cycling, weightlifting and swimming |
Until the site heals | Showers are fine; skip baths |
At least 1 week | Avoid flying |
Sources: [1]
When should you call a provider after thoracentesis?
You should call your provider after thoracentesis if you have chest pain, trouble breathing, or signs of infection. Contact them right away for: [1]
Chest pain, or pain when you take a deep breath
Coughing up blood
Sudden shortness of breath
Fever or chills
Swelling, bleeding or color change at the needle site
Thoracentesis at a glance
Question | Answer |
Other name | Pleural tap |
What it removes | Fluid from the pleural space (pleural effusion) |
Main goals | Find the cause of the fluid; ease breathing |
Anesthesia | Local numbing |
Imaging | Ultrasound or CT |
Setting | Usually outpatient |
Most common side effect | Soreness |
Back to work or school | Within a few days for most people |
Flying | Avoid for at least 1 week |
Sources: [1]
Conclusion
Thoracentesis is a common, low-risk procedure that drains fluid from around the lungs. It eases breathing and gives your care team a fluid sample that can explain why the fluid built up in the first place. Preparation is simple, the area is numbed, and most people go home the same day. [1]
Knowing what to expect can make the day feel far less stressful. Bring your list of medicines and supplements, ask your provider which ones to pause, and keep the warning signs above in mind during recovery.
Want to understand the condition behind the fluid? Explore our guides to heart failure, pneumonia and pleurisy, and save this page to bring to your next appointment. For more plain-language explainers reviewed by a physician, browse the Rinnit health library.
FAQ
What is a pleural tap?
A pleural tap is another name for thoracentesis. It is a procedure that uses a needle to remove fluid from the space between the lungs and the chest wall. [1]
Is thoracentesis a major procedure?
Thoracentesis is not a major procedure; it is a low-risk procedure that is usually done on an outpatient basis. Most people go home the same day. [1]
Are you awake during thoracentesis?
Yes, people are usually awake during thoracentesis because only a local numbing medicine is used. You may be asked to hold your breath or breathe out during the procedure. [1], [5]
Is coughing normal after thoracentesis?
Coughing for up to an hour after thoracentesis is normal. Call your provider if you cough up blood or have sudden shortness of breath. [1]
How long does it take to recover from thoracentesis?
Most people return to work or school within a few days of thoracentesis. Avoid strenuous activity for a few days and avoid flying for at least a week. [1]
Can pleural fluid come back after thoracentesis?
Pleural fluid can come back after thoracentesis, depending on its cause. Some people need repeat procedures, but providers limit how often they are done to reduce complications. [1]
Do I need to stop blood thinners before thoracentesis?
Your provider may ask you to pause blood thinners or antiplatelet drugs before thoracentesis. Only stop a medicine if your provider tells you to. [1]
When should I seek urgent care after thoracentesis?
Seek care after thoracentesis if you have chest pain, pain with deep breaths, coughing up blood, or sudden shortness of breath. Fever, chills, or swelling, bleeding or color change at the site also need a call to your provider. [1]
How long does thoracentesis take?
The procedure itself usually takes about 10 to 15 minutes, though preparation and monitoring add more time. Most people go home the same day.
Will I need a chest X-ray after thoracentesis?
Often, yes. Many providers order a chest X-ray or ultrasound afterward to check for a collapsed lung and to see how much fluid was removed.
Related Reading
Thoracostomy (Chest Tube Insertion): Purpose, Procedure, Risks and Recovery explains how a chest tube drains air or fluid around the lung.
Pleurodesis: Chemical vs. Mechanical, Procedure, Success Rates and Recovery describes a procedure that stops fluid or air from building up again.
Pneumothorax: Understanding Collapsed Lung Causes and Care covers collapsed lung, a possible complication of thoracentesis.
Paracentesis: Procedure, Risks, and Recovery explains the similar needle procedure that drains fluid from the belly.
References
Cleveland Clinic. Thoracentesis: Purpose, Procedure, Risks & Recovery. Cleveland Clinic. Last updated May 22, 2026. https://my.clevelandclinic.org/health/treatments/24254-thoracentesis
Lakkadghatwala R, Wilson A, Sabhaney V, et al. Ultrasound guidance compared to anatomic landmark approach for thoracentesis: A systematic review and meta-analysis. Am J Emerg Med. 2025;97:159-164. PMID 40738083. https://doi.org/10.1016/j.ajem.2025.07.049
Fong C, Tan CWC, Tan DKY, et al. Safety of Thoracentesis and Tube Thoracostomy in Patients With Uncorrected Coagulopathy: A Systematic Review and Meta-analysis. Chest. 2021;160(5):1875-1889. PMID 33905681. https://doi.org/10.1016/j.chest.2021.04.036
Lentz RJ, Lerner AD, Pannu JK, et al. Routine monitoring with pleural manometry during therapeutic large-volume thoracentesis to prevent pleural-pressure-related complications: a multicentre, single-blind randomised controlled trial. Lancet Respir Med. 2019;7(5):447-455. PMID 30772283. https://doi.org/10.1016/S2213-2600(18)30421-1
MedlinePlus. Thoracentesis. MedlinePlus Medical Encyclopedia. Last updated August 19, 2024. https://medlineplus.gov/ency/article/003420.htm
Medical disclaimer
This article is for general education and does not replace advice from your own doctor. Always follow the instructions of the care team treating you, and seek emergency care for severe chest pain or sudden trouble breathing.
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