synovialFluidAnalysis
Reviewed
Also called: Synovial Fluid Analysis, Joint Fluid Analysis, Arthrocentesis
A group of tests that checks for changes in synovial fluid to help diagnose the cause of joint pain, swelling, and inflammation. The analysis usually includes checking the fluid's appearance, chemical tests, and microscopic analysis for crystals, bacteria, and other substances.
Specimen: synovial fluid (joint fluid)
Why this test may be ordered
- Joint pain with a fever
- Joint swelling
- Redness over the joint
- A joint that feels warm to the touch
- Difficulty bending a joint
Preparation and collection
You may need to fast (not eat or drink) for several hours before the test. Your provider will let you know if you need to fast and if there are any special instructions. Tell your provider if you are taking any blood thinner medicines.
A procedure called arthrocentesis (joint aspiration). The provider cleans the skin, numbs the area, and inserts a needle into the joint to withdraw a sample of synovial fluid. The procedure usually takes less than two minutes.
Your joint may be sore for a couple of days after the procedure. Serious complications, such as infection and bleeding, may happen but are uncommon. Let your provider know if you have increased redness, swelling, or pain at the joint.
Understanding results
Your provider will interpret your results based on your symptoms, medical history, and other tests. The following patterns are based on the source.
- Normal synovial fluid: Synovial fluid is usually light yellow, clear, and a little sticky or stringy. This is a routine finding. Limitation: A normal result does not rule out all joint conditions. Next step: Routine
- Abnormal synovial fluid (cloudy, thicker or thinner than normal, or other changes): May be a sign of a type of arthritis (such as osteoarthritis, rheumatoid arthritis, or gout), a bleeding disorder, or a bacterial infection. Limitation: Your specific results will depend on what abnormalities were found. This test alone does not diagnose a specific condition. Next step: Prompt
- The source does not provide specific reference intervals, units, or performing laboratory details.
- Interpretation requires correlation with symptoms, medical history, and other tests.
- Serious complications from the procedure are uncommon but possible.
What to do next
If you have questions about your results, talk to your provider.
- What do my specific results mean for my joint symptoms?
- Do I need any other tests to confirm a diagnosis?
- What are the next steps based on my results?