A normal person’s urine occult blood test result should be negative. If urine occult blood 3+ can be seen in physiological conditions and pathological conditions. Physiological urine occult blood 3+ mostly does not require treatment; pathological urine occult blood 3+ is commonly seen in urinary system diseases, blood system diseases, autoimmune diseases, etc., which require prompt medical attention. I. Physiological: Positive urinary occult blood may occur after excessive strenuous exercise, and after resting for a few days and then rechecking, the urinary occult blood will often return to normal. If a female patient undergoes routine urinalysis during menstruation, she may also have a positive urine occult blood because of the retention error problem, in which case it is recommended that the patient be rechecked after the menstruation is clean to improve the accuracy of the test. Second, pathological: 1, urinary system diseases: a variety of acute and chronic nephritis, pyelonephritis, focal segmental glomerulosclerosis, cystitis, etc., because of the presence of inflammation, may lead to the occurrence of hematuria, urinary occult blood 3 +, may be accompanied by proteinuria, some patients even have renal hypoplasia situation. Some patients with urinary tumors and urinary stones may also have urinary occult blood 3+ due to tumor invasion of blood vessels or stones scratching the urethra; 2. Hematologic diseases: such as leukemia, aplastic anemia, thrombocytopenic disease, hemophilia, etc., may lead to urinary occult blood 3+ due to lack of clotting factors or reduced platelet levels; 3. Autoimmune diseases: such as systemic lupus erythematosus , dermatomyositis and other autoimmune diseases that involve the kidneys may also lead to urinary occult blood 3+; 4. Other: for example, when patients have rhabdomyolysis or hemolysis, etc., because the urine contains hemoglobin or myoglobin, which can lead to urinary occult blood 3+. Urinary occult blood is often positive after invasive urethral operations, and taking anticoagulants and side effects caused by chemotherapy drugs may also lead to urinary occult blood 3+.