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Fluid for Crystals
177.00
This test analyses body or joint fluid for the presence of crystals. It is essential for diagnosing gout, pseudogout and crystal-induced inflammation.
Turnaround time
Results available 1 day after arrival in lab. Doctor's report sent the day after results available (if required)
Biomarkers count
1
Same-Day Appointments
UKAS Accredited Labs
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Under 18? Patients under 18 can only be seen at GB Medlabs and Clinilabs, Monday to Friday only.
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Details about Fluid for Crystals
What is the Fluid for Crystals Test?
The Fluid for Crystals test involves microscopic examination of body fluid, most commonly synovial (joint) fluid, to identify the presence of crystals. These crystals form when certain substances, such as uric acid or calcium pyrophosphate, accumulate and crystallise within joints or tissues.
Crystal identification is performed using polarised light microscopy, which allows accurate differentiation between crystal types. This makes the test the gold standard for diagnosing crystal-induced arthropathies, particularly gout and pseudogout.
The test is often requested when joint inflammation is acute, painful and unexplained.
Why do I need a test for Fluid Crystals?
You may need this test if you experience sudden, severe joint pain, swelling and redness, especially if gout or pseudogout is suspected. Blood tests alone cannot definitively diagnose crystal-related joint disease.
Identifying crystals directly in fluid confirms the diagnosis and helps guide appropriate treatment, preventing unnecessary antibiotics or incorrect long-term management.
Symptoms and scenarios where testing is recommended:
- Sudden onset of severe joint pain
- Swollen, hot or red joints
- Suspected gout or pseudogout
- Recurrent joint inflammation
- Unclear cause of arthritis
- Monitoring known crystal arthritis
- Joint effusion of unknown origin
- Excluding infection in acute arthritis
Benefits of the Fluid for Crystals Test
- Gold standard for gout diagnosis
Directly confirms urate crystal presence. - Differentiates gout from pseudogout
Identifies crystal type accurately. - Guides correct treatment decisions
Prevents misdiagnosis and inappropriate therapy. - Rapid and definitive diagnosis
Provides clear diagnostic evidence. - Reduces unnecessary investigations
Avoids reliance on indirect blood markers alone. - Supports infection exclusion
Helps distinguish crystal arthritis from septic arthritis. - Essential in acute joint inflammation
Crucial for urgent diagnostic clarity. - Clinically validated diagnostic method
Widely accepted in rheumatology practice.
Step-by-Step: How Testing Works
Sample Collection Method
This test requires fluid collected by a clinician from the affected joint or body cavity.
Joint or Fluid Aspiration
- A clinician performs sterile aspiration of joint or body fluid.
- The sample is placed in a specialised container.
- The fluid is analysed under polarised microscopy for crystals.
- Results are reported with crystal type and presence.
Access your report
Results are shared with your referring clinician to guide immediate treatment decisions.
Your Results Explained
No Crystals Detected
No crystal structures seen in the fluid.
This makes crystal-induced arthritis less likely but does not fully exclude it.
Monosodium Urate Crystals
Needle-shaped, negatively birefringent crystals.
Diagnostics of gout.
Calcium Pyrophosphate Crystals
Rhomboid-shaped, positively birefringent crystals.
Indicative of pseudogout (CPPD disease).
Results are interpreted alongside symptoms, imaging and laboratory findings.
How It Works
Simple steps to get your results
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Choose your test online and book in seconds. Select your preferred clinic location or home visit option.
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Visit or Test at Home
Attend one of our UK or London clinics, arrange a home nurse visit, or use a finger-prick kit where available.
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Get Your Results
Your sample is analysed by accredited UK laboratories, with secure results delivered directly to you.
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WhatsApp UsHow to Prepare for Your Test
Follow these guidelines for accurate results
Sample Timing
Where possible, attend your blood test between 7am and 12pm. Please wait until any short-term illness or infection has fully resolved before testing. Avoid intense exercise for 24–48 hours beforehand, as this can affect certain markers.
Fasting & Hydration
Fasting is not always required, but some tests may recommend it. If fasting is advised, avoid food for 8–12 hours before your appointment and drink water only. Stay well hydrated, as this helps with sample collection and accuracy.
Medications & Supplements
Continue prescribed medications unless advised otherwise by your clinician. Avoid vitamin, mineral, or biotin supplements for at least 24–48 hours before your test, as these can interfere with results. If you are unsure about any medication or supplement, please let us know before your appointment.
Hormones & Menstrual Cycle
For hormone-related tests, timing within your menstrual cycle may be important. If relevant, follow any specific guidance provided on your test page.
If you have any questions or special circumstances, our team is happy to advise before your appointment.
Frequently Asked Questions
Most commonly joint (synovial) fluid.
Mild discomfort may occur during aspiration, but it is usually well tolerated.
Yes, it is the gold standard for diagnosis.
No fasting is required.
No, blood uric acid alone cannot confirm gout.
Often same day or within 24 hours.
Not completely, but it makes it less likely.
It helps exclude infection but may be combined with cultures.
Yes, especially if diagnosis is uncertain.
Treatment is guided based on crystal type and clinical context.
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