Cystatin C, Serum Concentration
This test measures the level of cystatin C, a protein produced by all cells in the body that helps regulate cell growth and division. It is often used to assess kidney function.
["Cystatin C helps evaluate kidney health and may be useful in diagnosing or monitoring kidney disease."]
Key facts at a glance
- LOINC
- 10969-4
- Short code
- Cys+HCys Ur Ql
- Synonyms
- Cys+HCys Ur Ql
- Category
- chemistry
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Specimen volume
- 10 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
- 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 a cystatin C test to check how well your kidneys are working. It can be useful for diagnosing kidney disease, especially in people with diabetes or high blood pressure, or when other kidney tests are unclear. Cystatin C is also sometimes used alongside creatinine to better estimate kidney function, as it does not depend on muscle mass.
What to Expect Before the Test
No special preparation is needed for this blood test. You may have a small needle inserted into your arm, and a few drops of blood will be collected into a tube. The process usually takes just a few minutes. If you have a blood clot disorder, let your provider know before the test.
How the Test Works
Blood is drawn from a vein in your arm and sent to a lab. There, a special test measures the amount of cystatin C in your serum. The result is compared to a standard to determine your cystatin C level.
What the Results Mean
Higher than expected levels of cystatin C may indicate kidney problems, such as chronic kidney disease. Lower levels might suggest conditions that affect protein production or kidney function differently. Your healthcare provider will discuss the results with you in the context of your overall health and other tests.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Cystatin C is a reliable marker for kidney function because it is produced by nearly all cells in the body and does not change much with muscle mass or diet. It is often used alongside creatinine to better assess kidney health, especially in people with diabetes or those who have had kidney function tests that are unclear. Higher levels can signal early kidney damage, which is important for preventing further decline.
Short name
Cystatin C
Frequently asked questions
How often should cystatin C be checked?
Can diet or exercise affect cystatin C levels?
Is there any pain or discomfort with 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