Lab test · Nephrology
Cystatin C
Kidney filtering rate
- Blood sample
- No fasting
- Report within 2 days
- Home collection
What this test is for
Kidney filtering rate
Cystatin C is a small protein made at a steady rate by nearly all cells in the body and cleared from the blood by the kidneys. If the kidneys filter less well, cystatin C builds up in the blood. Unlike creatinine, it is little affected by muscle mass, so it gives your doctor another way to estimate the kidney filtering rate (eGFR), especially when a creatinine result may be misleading.
Why a doctor may order it
- To confirm kidney function when a creatinine-based eGFR is borderline or unclear
- In people with unusually low or high muscle mass, such as frail older adults or very muscular people
- To help decide whether mild chronic kidney disease is really present
- When an accurate estimate of kidney filtration is needed before some treatments
How to prepare
Fasting: Not needed.
You do not need to fast or do anything special before a cystatin C test. Keep taking your regular medicines, but tell your doctor if you take steroid medicines or have a thyroid condition, as these can affect cystatin C levels.
At home
- Sample
- Blood sample
- How it works
- A trained sample collector comes to you and draws a small amount of blood from a vein in your arm. If your doctor has also asked for creatinine, both can usually be tested from the same visit.
- Report
- Within 2 days of collection.
What the results can mean
The result is reported with the laboratory's range and is often used to calculate an estimated glomerular filtration rate (eGFR). A higher cystatin C usually means the kidneys are filtering less well. Your doctor may combine it with creatinine for a more accurate estimate, and will interpret it with your urine tests, blood pressure and medical history rather than on its own.
What's included
One test: Cystatin C, from one blood sample.
Related tests
- Serum CreatinineCreatinine is a waste product made by the normal breakdown of muscle.
- Kidney Function Test (RFT)A kidney function test, also called a renal function test (RFT), is a group of blood tests that show how well your kidneys are filtering waste from the blood.
- Urine Albumin-Creatinine Ratio (ACR)This test compares the amount of albumin, a protein, with the amount of creatinine, a waste product, in a single urine sample.
- Blood UreaUrea is a waste product formed in the liver when the body breaks down protein.
- Serum ChlorideSalt & water balance৳150
- Serum Sodium (Na)Sodium (salt) level৳190
Questions people ask
What is the difference between cystatin C and creatinine?
Both are cleared by the kidneys and used to estimate kidney function. Creatinine comes from muscle, so it varies with muscle mass, diet and age, while cystatin C is much less affected by muscle mass.
Is cystatin C more accurate than creatinine?
It can be more reliable in people whose muscle mass is unusually high or low. Many doctors use both together, as a combined estimate is often more accurate than either one alone.
Can anything other than the kidneys change cystatin C?
Yes. Thyroid problems and steroid medicines can shift the level, so your doctor takes these into account when reading the result.
How much does a Cystatin C test cost in Dhaka?
With Mukti Health the price is ৳2,500, and the sample is collected at your home in Dhaka. You see the price again before you confirm the booking in the Mukti Health app.
Can I do the Cystatin C test at home in Dhaka?
Yes. Book it in the Mukti Health app and a trained sample collector comes to your home in Dhaka to take the blood sample. You do not need to go to a laboratory.
How long does the Cystatin C report take?
The report is usually ready within 2 days of the sample being collected.