Rheumatology• Updated 21 October 2026
Joint Fluid Analysis
A test of fluid drawn from a swollen joint to find the cause, such as gout or infection.
Results: Same day to a few days Specimen: Joint fluid
Quick Summary
Primary Purpose
To diagnose gout, joint infection and inflammatory arthritis.
What It Measures
Cells, crystals and bacteria.
Preparation
No special preparation.
Overview
Uric acid crystals confirm gout.
An infected joint needs urgent treatment.
What It Measures
Crystals
Uric acid or others.
White cells
Inflammation or infection.
Culture
Bacteria.
How It's Performed
- 01
Clean
Skin cleaned and numbed.
- 02
Aspirate
A needle removes fluid.
- 03
Relief
Removing fluid often eases pain.
Interpreting Results & Next Steps
Discuss with Doctor
Your doctor will explain what your result means and what happens next.
If values are High:
Crystals point to gout; many white cells or bacteria suggest infection.
Sources and further reading
Last updated 21 October 2026. For more detail, see these trusted health organisations.
- Synovial Fluid Analysis(opens in a new tab) · MedlinePlus, US National Library of Medicine