Arthrocentesis: What It Is and What to Expect
Medically reviewed by Sumiran Racherla, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor provides Arthrocentesis?
Arthrocentesis, also called joint aspiration, is done by a rheumatologist (a joint doctor) or an orthopedic surgeon (a bone and joint doctor). Most of the time it is done in a clinic, hospital, or emergency room. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What it is
Arthrocentesis removes fluid from a joint with a needle and a syringe. The fluid is called synovial fluid, the thick liquid that cushions the joint. The fluid goes to a lab, where it is checked for signs of disease. Removing extra fluid can also relieve pain and other symptoms.
Why a doctor might recommend it
Doctors use arthrocentesis to find the cause of joint pain and swelling. The fluid can show crystals that mean gout or pseudogout. It can show bacteria, which point to a joint infection. It can also show signs of inflammation, like in rheumatoid arthritis. The same needle can deliver medicine into the joint to ease pain and swelling.
How to prepare
You may need to fast (not eat or drink) before the test. Your provider will let you know if you need to fast and what special steps to follow. Tell your provider if you are taking any blood thinner medicines. Also tell them about any allergies and health problems. Follow your doctor's instructions about fasting and your medicines before the test.
What happens during it
You sit or lie down so the doctor can reach the joint. The skin over the joint is cleaned. Numbing medicine is injected, or a numbing cream is put on the skin. Ultrasound may be used to help find the fluid in the joint. The doctor puts a thin needle into the joint space and draws fluid into a syringe. The doctor tries to remove as much fluid as possible. Then the needle comes out and a bandage goes on. The whole thing usually takes less than two minutes.
Recovery
The joint may be sore for a couple of days after the procedure. Your provider may ask you to limit your activity, use ice packs, or elevate the joint. Follow any other steps your provider gives you.
Risks and side effects
Arthrocentesis is very safe, and problems are rare. They include infection, bleeding into the joint, and an allergic reaction to the numbing medicine. The spot may look bruised or swollen. Get care right away if you have increased redness, swelling, or pain at the joint. A joint infection is a severe problem if it is not identified and treated promptly.
Who performs it
A doctor performs arthrocentesis, usually in a clinic, hospital, or emergency room. A nurse or another team member may help prepare you and monitor you during the procedure.
Common questions
How long does arthrocentesis take?
The procedure usually takes less than two minutes.
Will it hurt?
You should not feel pain during the procedure. You get numbing medicine first. You may still feel some discomfort.
What can the joint fluid show?
The lab checks how the fluid looks and what is in it. Crystals can point to gout or pseudogout. Bacteria can mean infection. Normal synovial fluid is light yellow, clear, and a little sticky or stringy.
How does a direct primary care or concierge doctor fit in?
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance.
Sources
- MedlinePlus - Synovial Fluid Analysis
- National Library of Medicine, NCBI Bookshelf - Arthrocentesis (StatPearls)
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
