Cystatin C, Serum Concentration
This test measures the level of cystatin C, a protein produced by all cells in your body. It helps assess how well your kidneys are filtering waste from your blood.
["Cystatin C is a simple blood test that can help check kidney function."]
Key facts at a glance
- LOINC
- 59220-4
- Short code
- CGA-PL
- Synonyms
- CgA Plr-aCnc
- Category
- chemistry
- Sample
- fluid
- Container
- Sterile, leak-proof container; plain red-top tube or specific immunoassay-compatible tube
- Units
- N/A
- Ref low
- 0
- Ref high
- 93
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Enzyme-Linked Immunosorbent Assay (ELISA) / Chemiluminescent Immunoassay (CLIA)
- CPT
- 83519
- SNOMED
- 104659003
- Specimen volume
- 1-2 mL of pleural fluid
- Stability
- Room temperature: 8 hours; Refrigerated (2-8°C): 48 hours; Frozen (-20°C or below): 3 months
- Hemolysis max
- 300
- TAT
- 24–72 hours
- Order
- routine
Why Is This Test Done?
Your doctor may order this test to monitor kidney health, especially if you have diabetes, high blood pressure, or a family history of kidney disease. It can also be used to track kidney function before or after treatments like chemotherapy or surgery.
What Does a Result Mean?
Higher than expected levels may indicate poor kidney function, while lower levels might suggest overhydration or other conditions. Your doctor will interpret results in relation to your overall health and medical history.
How Is the Test Performed?
A blood sample is taken from a vein, usually in your arm. The sample is sent to a lab where it is analyzed to measure cystatin C levels using an immunoassay method.
What Should You Do Before the Test?
No special preparation is needed, but inform your doctor about any medications you’re taking, especially those that affect kidney function. Avoid strenuous activity the day of the test.
Reference range
Reference ranges for Chromogranin A in pleural fluid are not well established; results should be interpreted in conjunction with clinical findings and other diagnostic tests. Serum reference ranges typically <93 ng/mL may not directly apply to pleural fluid.N/A
No special patient preparation required. Fasting is not necessary for this test.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Cystatin C
Frequently asked questions
How often should I get this test if I have kidney issues?
Can diet or hydration affect cystatin C levels?
Is this test painful?
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