Cystatin C, Serum Concentration (Quantitative)
This test measures the level of cystatin C, a protein produced by all cells in your body. It helps assess your kidneys' function.
["Cystatin C is a simple blood test to check kidney health."]
Key facts at a glance
- LOINC
- 100676-6
- Short code
- CMV DNA Bld NAA+probe-Log IU
- Synonyms
- CMV DNA Bld NAA+probe-Log IU
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- probe-amp-tar
- Specimen volume
- 3 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why Is This Test Done?
Your healthcare provider may order this test to evaluate kidney function, especially if you have symptoms like fatigue, swelling, or changes in urine output. It’s also used to monitor kidney disease progression or response to treatment. Cystatin C is useful because it doesn’t depend on kidney filtration rates like other tests, making it more reliable in some cases.
What to Expect Before the Test
No special preparation is needed. You may have a small needle inserted into your arm to draw blood. If you’re on blood thinners, let your provider know before the test.
What Happens During the Test?
A healthcare professional will clean your arm and insert a needle to collect a small amount of blood. The blood will be sent to a lab for analysis.
What Are the Results?
Results are typically reported as a concentration value in milligrams per deciliter (mg/dL). Your provider will interpret the result in relation to your health and medical history.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Cystatin C is a sensitive marker for kidney function. Elevated levels may indicate reduced kidney function or kidney disease, even in people with normal blood pressure and no other symptoms. It can also help detect kidney problems early, especially in individuals with diabetes or high blood pressure. This test is often used alongside other measures, like creatinine, to get a fuller picture of kidney health.
Short name
Cystatin C
Frequently asked questions
Why might my doctor order this test?
How does cystatin C differ from creatinine?
Can I eat or drink before this test?
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