1,25-dihydroxyvitamin D (calcitriol)
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Cystatin C
88.00
This test measures Cystatin C, a highly sensitive marker of kidney filtration. It can detect early kidney impairment before standard markers change.
Turnaround time
1-2 days
Biomarkers count
1
Same-Day Appointments
UKAS Accredited Labs
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Details about Cystatin C
What is a Cystatin C test?
A Cystatin C test measures the level of cystatin C in your blood, a protein produced by all nucleated cells and filtered almost exclusively by the kidneys.
Unlike creatinine, cystatin C is not influenced by muscle mass, age, gender, or diet, making it a more accurate and earlier indicator of kidney filtration (GFR).
Why do I need a Cystatin C test?
Kidney problems often develop silently and may not be detected early by creatinine or eGFR alone.
Reasons for testing include:
• Monitoring kidney function more accurately
• Diabetes or high blood pressure
• Family history of kidney disease
• Long-term medication use affecting kidneys
• Unexplained fatigue or swelling
• Borderline creatinine or eGFR results
• Athletes or muscular individuals (where creatinine is misleading)
Symptoms that may prompt testing include:
• Swelling in legs or face
• Frequent urination
• Foamy urine
• Persistent fatigue
• High blood pressure
Benefits of the test
1. Detects kidney impairment earlier than creatinine
2. More accurate GFR assessment
3. Not affected by muscle mass or diet
4. Useful in diabetes and hypertension monitoring
5. Identifies early kidney stress
6. Supports accurate kidney risk assessment
7. Useful when creatinine results are borderline
8. Provides a clearer picture of filtration capacity
Expanded benefit explanation
Cystatin C is considered one of the most reliable early markers of kidney function and is increasingly used in advanced kidney assessment.
Step-by-step — How testing works
We offer two UK-wide testing options:
Clinic testing
• Choose nearest UK clinic
• Blood sample collected
• Laboratory analysis performed
• Results securely returned
Home visit (+£60)
• Phlebotomist visits you
• Blood sample collected safely
• Sample sent to lab
• Results delivered confidentially
Your results explained
Low levels
Typically not clinically significant.
Normal levels
UK reference range: 0.53 – 0.95 mg/L
Indicates normal kidney filtration.
High levels
May indicate reduced kidney filtration and early kidney impairment.
How It Works
Simple steps to get your results
1
Book Online
Choose your test online and book in seconds. Select your preferred clinic location or home visit option.
2
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.
3
Get Your Results
Your sample is analysed by accredited UK laboratories, with secure results delivered directly to you.
Take control of your health with London Blood Tests
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
It measures Cystatin C protein levels in the blood to assess kidney filtration efficiency.
In many cases, yes. It is less affected by muscle mass and can detect early kidney dysfunction more accurately.
No fasting is required.
People with diabetes, hypertension, cardiovascular disease, or unclear creatinine results.
Some conditions and medications may influence results, which is why clinical context matters.
Yes. It provides a more accurate kidney assessment when muscle mass skews creatinine levels.
Yes. We offer at-home phlebotomy blood draws across various UK locations.
Testing is performed in UKAS-accredited laboratories using validated clinical assays.
Results are typically available within 10 business days.
A GP consultation is optional, but recommended if results are abnormal or you have kidney-related symptoms.
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