A routine urine test for occult blood (++++) indicates an abnormal increase in red blood cells in the urine. Normal adult urine does not contain red blood cells, and when a bleeding disorder occurs, it can make the red blood cells in urine abnormally increase. There are several common diseases, such as urinary tract infections. Severe urinary tract infections, which cause bleeding from the mucosa of the urinary tract, can cause negative urine occult blood. In addition, urinary system stones can irritate the mucosa of the urinary tract, causing mucosal bleeding and causing positive urine occult blood. Urological tumors are also a relatively common disease that causes positive urinary occult blood. In addition, for chronic kidney diseases, such as chronic nephritis, nephrotic syndrome, etc., can also cause an abnormal increase in red blood cells in the urine, resulting in positive urine occult blood. Patients should further improve the relevant examination, combined with other symptoms accompanying the patient, to make a clinical diagnosis.