Cystatin C Levels - Kidney Screening Test in Tooting

The Cystatin C test measures the level of cystatin C protein in your blood, a reliable marker of how well your kidneys are filtering waste. Unlike creatinine-based tests, cystatin C is not affected by muscle mass, diet, or body composition, making it a more accurate measure of kidney function for a wider range of people. A simple blood sample is all that is needed, with no fasting required.

Who Should Get Tested?

Kidney disease often progresses silently, showing no symptoms until significant damage has occurred. Among UK adults aged 35 and over, 22% have some stage of chronic kidney disease. You should consider a Cystatin C test if you experience persistent fatigue, swelling in the hands or feet, changes in urine output or colour, or unexplained weight changes. The test is particularly valuable for people where standard creatinine tests may be unreliable, including the elderly, children, those with very high or low muscle mass, amputees, and people with liver cirrhosis or severe obesity.

Understanding Your Results

Elevated cystatin C levels suggest your kidneys may not be filtering waste efficiently. Your clinic team will explain your result and recommend further investigation or lifestyle changes if needed.