Urine occult blood positive ++ indicates an abnormal increase in red blood cells in the urine, normal urine test urine occult blood is usually negative. There are several reasons for the abnormal increase of red blood cells in urine: 1, strenuous exercise and activity can easily cause positive urine occult blood, which will improve after review; 2, urinary tract infection can also cause bleeding in the mucosa of the urinary tract, causing an increase in red blood cells in urine; 3, urinary system stones, which are also a very common cause of positive urine occult blood; 4, urinary tumors, a small amount of bleeding in the early stage of the tumor can also cause abnormal urine occult blood, and The urine occult blood positive; 5, urine occult blood + + may be nephritis. It is necessary to clarify the specific causative factors according to the other accompanying symptoms, combined with the relevant auxiliary tests.