Cystatin C

Cystatin C is a small protein produced naturally by nearly all cells in your body that serves as a marker for how well your kidneys are filtering waste from your blood. Unlike older kidney function tests, Cystatin C levels remain remarkably stable regardless of age, muscle mass, or diet, making it a more reliable indicator of kidney health across different populations. Scientists and doctors increasingly use Cystatin C measurements to detect early kidney disease and monitor kidney function in patients, particularly those where traditional tests might give misleading results.