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Synovial fluid analysis

Synovial fluid analysis

Synovial fluid analysis


What is this test?

This test detects characteristics of synovial fluid (fluid around the joints) such as the volume, color, or clarity. It is also used to measure biochemical parameters of synovial fluid such as the amount of glucose, uric acid, or total protein. This test is used to evaluate and manage joint diseases, such as suspected septic arthritis, gout or pseudogout, or inflammatory or non-inflammatory arthritis.

Why do I need this test?

Laboratory tests may be done for many reasons. Tests are performed for routine health screenings or if a disease or toxicity is suspected. Lab tests may be used to determine if a medical condition is improving or worsening. Lab tests may also be used to measure the success or failure of a medication or treatment plan. Lab tests may be ordered for professional or legal reasons. You may need this test if you have:

  • Arthritis
  • Brucella arthritis
  • Gout
  • Osteoarthritis
  • Septic arthritis

How should I get ready for the test?

An arthrocentesis is a procedure that requires written consent. Review the consent form with the healthcare worker and ask any questions that you have before signing the consent form.

Tell the healthcare worker if you have a medical condition or are using a medication or supplement that causes excessive bleeding. You should also report if you have a history of allergic or other reactions to local anesthetics. Blood tests may need to be done before an arthrocentesis.

How is the test done?

Synovial fluid is the fluid around the joints. A synovial fluid sample is obtained by a procedure called an arthrocentesis. The skin over the joint will be cleaned, and a local anesthetic will be used to numb the tissue at the insertion site. A needle will be inserted into the space around the joint, and fluid collected into a syringe. After enough synovial fluid has been collected, the needle will be removed.

How will the test feel?

The amount of discomfort you feel will depend on many factors, including your sensitivity to pain. Communicate how you are feeling with the person doing the procedure. Inform the person doing the procedure if you feel that you cannot continue with the procedure.

During an arthrocentesis, a local anesthetic is given to numb the procedure area. You may feel mild discomfort or stinging when the numbing medicine is injected. You may feel pressure or discomfort during the procedure. Brief pain may be felt as the needle passes through the joint membrane. Your procedure site may be sore for several days.

What should I do after the test?

After an arthrocentesis is completed, pressure may be held to the site, and a bandage secured over the puncture site. If a large amount of fluid is removed, an elastic wrap may be used to support your joint. To treat swelling and pain, you may place cold packs over the joint. Avoid heavy use of the joint for a few days. If you have difficulty using the affected arm or leg after the procedure, contact your healthcare worker.

You will be given instructions for how to care for your bandage and the signs and symptoms of infection to watch for. Contact your healthcare worker if you have a fever or increased pain, and if you see increasing redness, swelling, or pus at the procedure site.


You have the right to help plan your care. To help with this plan, you must learn about your health condition and how it may be treated. You can then discuss treatment options with your caregivers. Work with them to decide what care may be used to treat you. You always have the right to refuse treatment.