Urine occult blood 3+ indicates a positive urine occult blood test, which can be hematuria, hemoglobinuria or myoglobinuria. The most common clinical condition is hematuria, which may be caused by acute injury, urinary tract infection, urinary stones, urinary tumors, and systemic diseases, etc. In addition, certain physiological factors can also lead to it. 1. Acute injury: the lower body suffered acute trauma, resulting in local damage to the urethra or bladder, causing bleeding, blood mixed with urine, it will lead to urine occult blood 3 +. 2. Urinary system infection: for example, acute nephritis, acute cystitis, etc., due to the presence of infection, and the infection is more serious, causing damage to the urinary tract tissues, it will cause urinary occult blood 3 +, may also be accompanied by pain in urination, urinary frequency, fatigue, fever and other symptoms. 3. urinary stones: such as urethral stones, ureteral stones, etc., the stone in the process of movement leads to local bleeding, will cause urinary occult blood 3 +, may also be accompanied by urinary difficulties, urinary frequency, urinary pain and other symptoms, and even lead to urinary tract obstruction, will cause hydronephrosis. 4. Urological tumors: for example, renal tumors, tumor surface tissue necrosis and bleeding, which will lead to urinary occult blood 3+, and there will also be naked eye painless hematuria. 5. Systemic diseases: urinary occult blood 3+ may also be related to some systemic diseases, such as thrombocytopenic purpura, hemophilia, sepsis, etc., which can lead to urinary occult blood 3+. 6. Physiological factors: such as women’s menstrual period, menstrual blood mixed into the urine, after strenuous exercise may appear positive urinary occult blood, can be returned to normal after rest. It is recommended that patients with urinary occult blood 3+ go to the hospital in time to improve the examination, to clarify the specific causes, and timely compliance with the doctor’s instructions for treatment.