Low creatinine in kidney function is divided into physiological and pathological causes. Physiological causes are common, such as low protein intake, low muscle content, pregnancy, etc. Pathological causes such as early diabetic nephropathy, tumors and other consumptive diseases. 1. Physiological reasons: patients with long-term partiality, malnutrition, resulting in the gradual consumption of body protein, creatinine source decline, or muscle content is too small, may appear in renal function creatinine is low, can improve the patient’s eating habits, usually do not need special treatment. During pregnancy, women may increase the glomerular filtration rate, which will also make creatinine lower than normal. 2. Pathological reasons: patients in the early stage of diabetic nephropathy may lead to a compensatory increase in glomerular filtration rate, so that creatinine excretion increases, and the phenomenon of decreasing creatinine level. Tumor and other consumptive diseases may also consume protein in the body, making the muscle content become less, resulting in low creatinine. There may be other reasons for low creatinine, so it is recommended that patients go to regular hospitals in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or therapy under the guidance of the doctor.