Negative urine occult blood is a normal indicator. In the routine urine test, the item of urine occult blood is included. A normal person is negative, which means there are no red blood cells in the urine test. If urine occult blood appears positive, further tests are needed. The most common cause of urine occult blood is glomerulonephritis. It also includes other diseases other than kidney, such as urinary tract infection, urinary tract stone and urinary tract tumor, which can cause positive urine occult blood. In patients with glomerulonephritis, in addition to urinary occult blood, there is also a combination of urinary protein. Patients with urinary tract infections may also have a combination of urinary frequency, urinary urgency, and urinary pain. Patients with urinary stones will have a combination of back pain.