Whether creatinine 120μmol/L is serious or not depends on the condition of the patient. 120μmol/L creatinine belongs to elevated creatinine, which usually indicates kidney function impairment, and it may be caused by physiological reasons such as fatigue, excessive water loss, or pathologic reasons such as renal diseases, etc. If physiological reasons are caused, it is usually not serious. Physiological causes are usually not serious, while pathological causes are relatively serious. 1. Exhaustion: patients who often stay up late at night, work under too much pressure and overwork may have a transient increase in creatinine, and these patients should pay attention to rest, keep a good work and rest and maintain a good state of mind, and generally creatinine will return to normal. 2. Large amount of water loss: such as vomiting, high fever and sweating, etc., due to the reduction of circulating blood volume in the body, blood concentration, blood creatinine will often increase, through rehydration can be relieved, usually not serious. 3. Kidney diseases: such as glomerulonephritis, hypertensive nephropathy, nephrotic syndrome, lupus nephritis and other patients, if there is no standardized treatment, often lead to creatinine increase, this situation is more serious, indicating that the kidneys have been seriously damaged, and often need to actively treat the primary disease. Patients with creatinine 120μmol/L should go to the hospital in time to find out the cause of the disease, and actively cooperate with doctors for standardized treatment.