A cystatin C value of 1.75 mg/L is within the normal range and is usually not considered high. Adult serum cystatin C ranges from 0.6 to 2.5 mg/L. Therefore, a cystatin C of 1.75 mg/L is within the normal range and is not considered high. However, the normal range of values may vary slightly from laboratory to laboratory, so it is recommended to consult your local hospital. The original urinary cystatin C in the proximal tubule is almost completely taken up by the epithelial cells, decomposition, do not return to the blood, only a small amount of urinary excretion, therefore, the serum cystatin C level is a sensitive and specific indicator reflecting the glomerular filtration function. If patients find abnormal cystatin C, it is recommended to go to regular hospitals in a timely manner, improve the examination to clarify the cause of the disease, and then give targeted treatment or therapy under the guidance of the doctor.