Whether occult blood 3+ is serious or not is usually related to the cause of urinary occult blood, physiological causes are usually not serious, while pathological causes may be more serious, we should pay attention to find the cause of urinary occult blood, and give active treatment. Urine occult blood 3 + usually may be due to the presence of red blood cell rupture in the urine, the increase in red blood cells in the urine and rupture will lead to an increase in hemoglobin in the urine, resulting in a positive urinary occult blood. Physiological causes, such as strenuous exercise, high temperature, mental stress and other factors caused by urinary occult blood, usually not serious. Pathological factors such as acute nephritis, urinary stones, urinary tumors and inflammation caused by the relatively serious, the development of the disease can appear naked eye and microscopic hematuria, renal function decline, etc.; if the chronic nephritis caused by hematuria, no proteinuria and renal function abnormality, the condition is generally mild, but need to be reviewed regularly. It is recommended that patients with 3+ occult blood should go to the hospital in time to improve the relevant examinations, and actively treat under the guidance of the doctor to avoid delaying the condition.