Cystatin is cystatin C. The normal range is <1.03 mg/L, with 1.53 mg/L above normal. If the cystatin C value is high, it is generally not serious. If it is accompanied by increased creatinine and urea nitrogen values, it is relatively serious and prompt medical attention is recommended. 1. Increased cystatin C alone: cystatin C can reflect the function of the kidneys, and is one of the indicators for early judgment of glomerular filtration impairment. If only cystatin C is elevated, without creatinine and urea nitrogen elevation, this situation is generally not serious. 2. Increased cystatin C with increased creatinine and urea nitrogen: cystatin C1.53mg/L with increased creatinine and urea nitrogen suggests that the patient is likely to have renal failure, and metabolic disorders and multi-system symptoms will occur. Therefore, this situation is generally relatively serious. It is recommended that patients go to regular hospitals in time, and actively cooperate with the treatment after clarifying the cause of the disease, so as not to delay the condition.