High cystatin C suggests that renal function may be abnormal, and the cause of renal impairment should be clarified, whether it is primary or secondary renal disease, and the use of hormones (prednisone acetate), antihypertensive drugs (valsartan), hypoglycemic drugs (dagliflozin), etc. should be targeted. Cystatin C, a cysteine protease inhibitor, is a more sensitive endogenous marker reflecting changes in glomerular filtration rate, which can be elevated for a variety of reasons. 1. Primary nephropathy: first of all, renal puncture and pathological examination should be carried out, according to the pathological results to determine the medication program, the use of hormone or immunosuppressant treatment, such as prednisone acetate, cyclophosphamide and so on. 2. Secondary nephropathy: etiologic treatment should be carried out to control the primary disease. If the renal function abnormality is caused by hypertension, according to the situation, we can use Prilosec or sartan antihypertensive drugs, such as Benadryl and Valsartan, to control the blood pressure in the normal range and protect the renal function. If the renal function abnormality is caused by diabetes mellitus, then oral dagliflozin can be used to control blood sugar, to avoid aggravation of renal function damage. All of the above medications should be used under the guidance of a doctor, avoid self-medication. If the serum cystatin C is high, you should go to the regular hospital for further examination to clarify the cause of the disease and timely treatment.