There are many causes of positive urinary occult blood, and there are four common causes: 1) oral anticoagulant drugs, such as aspirin and poliovirus, which inhibit the body’s coagulation mechanism and cause positive urinary occult blood, which often disappears after stopping the relevant drugs; 2) surgical diseases of the urinary system, such as urinary tract infections, urinary stones and urinary tumors; 3) medical diseases of the urinary system, such as glomerulonephritis nephritis, etc.; 4. Positive urinary occult blood that cannot be clinically identified. No matter what the cause of positive urine occult blood is, we must go to the hospital for routine urine examination, urinary ultrasound examination, or even urinary CT examination, after excluding some more serious diseases such as urinary tumors and stones, if the occult blood is positive only because of oral anticoagulant drugs or for unknown reasons, we can perform regular urine examination and observe the changes of occult blood without special treatment.