The most common causes of female occult blood (1+): 1, women in the menstrual period to retain urine, may lead to menstrual contamination of the specimen, caused by red blood cells in the urine, so it is recommended that women to avoid the menstrual period to do routine urinalysis. 2, urinary diseases, such as acute glomerulonephritis, acute glomerulonephritis, chronic nephritis and so on will lead to urinary occult blood (1+). Common diseases like urinary tract infections, urinary stones or urinary tumors can lead to urinary occult blood(1+) in women.3, systemic diseases, autoimmune diseases, such as systemic lupus erythematosus and desiccation syndrome can lead to occult blood(1+) in women. In addition, thrombocytopenic purpura can also lead to urinary occult blood(1+) in women.