Occult blood 1+, divided into physiological causes and pathological causes. The former includes contamination of menstrual blood during the physiological period of women, and the latter includes inflammation, stones, tumors, etc. Physiological causes: urine routine examination during menstruation may be positive for urinary occult blood, and urine routine examination can be repeated after menstruation. Pathological causes: mainly include inflammation, stones, tumors and so on. Inflammation includes glomerulonephritis, pyelonephritis, cystitis and so on. Stones include kidney stones, ureteral and bladder stones, etc. Either type of stone may cause occult blood. In addition, benign and malignant tumors of the kidney, bladder and ureter may also cause occult blood. There are more reasons for occult blood 1+, it is recommended to visit the hospital as soon as possible for examination to clarify the cause of the disease and actively cooperate with the doctor for treatment.