Whether high creatinine and normal urine ultrasound is serious depends on the cause of high creatinine. If it is caused by physiological reasons such as higher muscle content or eating more meat, it is usually not serious at this time; if it is caused by pathologic reasons such as acute kidney injury, it may not be serious if reversible factors are corrected positively, but it may be more serious if the condition is more serious and the treatment effect is not good. 1. Physiological reasons: some patients with elevated creatinine may be due to their own muscle content is higher, or usually eat more meat, more exercise caused by routine urinalysis and ultrasound of the urinary system and other related tests do not see any abnormality, clear kidney without obvious diseases, such cases are usually not serious. 2. Pathological causes: if pathological causes such as acute kidney injury, when gastrointestinal fluid loss, massive blood loss and other pre-renal factors leading to acute kidney injury, creatinine may be high, but urine ultrasound is normal, if the reversible factors are corrected positively, renal function is gradually recovered, may not be serious, if the condition is more serious, the effect of the treatment is poor, it may be more serious. If patients find high creatinine, it is recommended to 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.