Cystatin C Quantitative Measurement, Serum
This test measures the level of cystatin C, a protein produced by all cells in your body that helps regulate cell growth. It’s often used to assess kidney function.
["Cystatin C helps monitor kidney health and may be used alongside other tests to check for kidney disease."]
Key facts at a glance
- LOINC
- 34720-3
- Short code
- CMV DNA Spec NAA+probe-aCnc
- Synonyms
- CMV DNA Spec NAA+probe-aCnc
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- probe-amp-tar
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why Is This Test Done?
Your doctor may order this test to evaluate kidney function, especially if you have symptoms like fatigue, swelling, or changes in urine output. It can also be used to monitor kidney disease progression or guide treatment decisions, such as for patients on dialysis or with certain medications.
How Is the Sample Collected?
A blood sample is drawn from a vein, usually in your arm, by a healthcare professional. You may feel a small pinch when the needle goes in, but the process is quick. The blood is then sent to a lab for testing.
What Should You Know Before Testing?
No special preparation is usually needed, but you may be asked to avoid certain medications or foods for a short time if instructed by your doctor. Drink plenty of water the day of the test to help your kidneys function normally.
What Are Common Results?
Results are typically reported as a concentration level of cystatin C in the blood. While reference ranges can vary by lab, higher levels may indicate reduced kidney function, while lower levels may suggest overproduction or other conditions.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Cystatin C is a more reliable marker than traditional blood tests like creatinine for assessing kidney function, especially in people with diabetes, older adults, or those with muscle disorders. It can help detect early kidney damage or monitor kidney disease over time, as it doesn’t depend on muscle mass or diet.
Short name
Cystatin C
Frequently asked questions
How long does it take to get my results?
Do I need to fast before this test?
Can diet or medications affect cystatin C levels?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy