Can a urine test be done during menstruation?

During menstruation, a urine test can generally be performed, but it may affect the accuracy of some test results. Urinalysis mainly includes urine routine, urine culture, and other items. The mixing of menstrual blood may lead to abnormal increases in indicators such as red blood cells and white blood cells. In urine routine examination, menstrual blood contamination may lead to false positive occult blood in urine. At this time, microscopic examination should be combined to determine whether there is true hematuria. If a large number of flat epithelial cells or vaginal secretions are found in urine sediment microscopy, it suggests that the sample may be contaminated. In urine culture examination, the presence of menstrual blood may increase the probability of false positive bacterial culture, and clinical symptoms should be combined to determine whether infection exists. For hormone testing such as urinary progesterone, urinary follicle stimulating hormone, etc., there are physiological fluctuations at different stages of the menstrual cycle, and the sampling time should be indicated. When precise tests such as urine microalbumin and urine red blood cell morphology are required, menstrual blood interference may directly affect clinical judgment. The presence of endometrial cells in urine may be misdiagnosed as abnormal shedding cells, which can interfere with the screening results of urinary system tumors. Some special tests, such as uroporphyrin and hemosiderin in urine, may cause abnormal chemical reactions due to menstrual blood components.

It is recommended to avoid urine testing during menstruation as much as possible, and if necessary, use a urinary catheter for sampling to reduce contamination. Before collection, it is necessary to clean the perineum, discard the front urine, and collect the middle urine sample. If the test results are abnormal but there are no clinical symptoms, a follow-up examination can be conducted after the end of menstruation. Before conducting a urine test, the doctor should be informed of the current stage of the menstrual cycle in order to interpret the report reasonably. Daily attention should be paid to keeping the external genitalia clean, avoiding excessive exercise that can cause menstrual blood reflux, and wearing breathable cotton underwear to reduce the risk of infection.