Positive urinary occult blood may be caused by physiological reasons such as strenuous exercise, and may also be caused by pathological reasons such as urological diseases, common glomerular diseases, urinary stones, renal tumors, and non-urinary diseases such as sepsis, epidemic hemorrhagic fever. 1. Physiological reasons: normal human urine occult blood test is negative. If the normal people who usually have less exercise, exercise hematuria may occur after a sudden increase in the amount of exercise, positive urinary occult blood, but this is only transient, do not need special treatment. 2. Pathologic causes: (1) Urological diseases: such as glomerular diseases, most of which are manifested by hematuria, proteinuria, hypertension and edema; when renal stones or ureteral stones are present, the friction of stones on the mucous membrane leads to mucous membrane hemorrhage and then hematuria; renal tumors also cause painless hematuria of the naked eye when invading calyxes and renal pelvis. (2) Non-urinary diseases: sepsis, epidemic hemorrhagic fever, leukemia, aplastic anemia, etc. may also cause increased urinary erythrocytes and positive urinary occult blood. Positive urinary occult blood may also have other reasons, it is recommended that the patient to the regular hospital in time to improve the examination to clarify the cause of the disease, under the guidance of the doctor to the targeted treatment or treatment.