Normal cystatin C and high creatinine may be caused by physiological factors such as consuming too much meat or doing a lot of exercise, or pathologic factors such as some extra-renal diseases such as hypertension. 1. Physiological factors: some patients with high creatinine may be due to the high muscle content of the patients themselves, or usually eat more meat, exercise more caused by routine urinalysis and ultrasound of the urinary system and other related examinations do not see any abnormality, and clear renal disease is not obvious, cystatin C can be normal. 2. Extra-renal diseases: cystatin C is an indicator of glomerular filtration function, and its sensitivity is often higher than creatinine. If cystatin C is normal and creatinine is high, it often indicates that there is no problem with the kidneys, and most of them are caused by extra-renal diseases. For example, hypertension patients with unstable blood pressure or overexertion may lead to high creatinine but normal cystatin C. If the patient finds that creatinine is high, he/she may have a high blood pressure. If patients find high creatinine, it is recommended to go to regular hospitals in time to estimate the glomerular filtration rate of the patient, improve the examination to clarify the cause of the disease, and then give targeted treatment or therapy under the guidance of the doctor.