Urinary occult blood does not always have an inflammatory cause. Infectious diseases such as pyelonephritis, cystitis, urethritis, etc., can indeed cause positive urinary occult blood. In addition, the following diseases can also cause positive urine occult blood: 1. urological tumors, stones, tuberculosis, trauma, etc. 2. nephrotic syndrome, glomerulonephritis, immune diseases, blood disorders, long-term use of anticoagulant drugs, hemolysis and other medical diseases. 3. certain drug side effects can also cause positive urine occult blood, such as cyclophosphamide. 4. some patients present with post-exercise hematuria, related to strenuous exercise. 5, Some patients with unknown causes and negative indications for both ultrasound and CT need regular review and dynamic observation.