The dark color on the 1st day of menstruation is normal and usually does not require treatment. The endometrium is just shed on the 1st day of menstruation, the menstrual volume is relatively small, and the menstrual blood stays in the body for too long, which may easily cause the darkening of menstrual blood. A small amount of menstrual blood passes through the acidic environment of the vagina, which can easily lead to darkening of menstrual blood. If the darkening of menstrual blood is caused by gynecological inflammation, vaginal discharge examination can be performed and cefoxitin or metronidazole can be used to treat gynecological inflammation under the guidance of a doctor. The color of menstrual blood will recover on its own after the inflammation is cured. The black menstrual blood caused by cold in the uterus can take warming pills, and it is also recommended to drink more brown sugar water. Those caused by endocrine disorders can be regulated with hormonal drugs under the guidance of a doctor, and it is best to choose appropriate drugs according to the results of the examination. Black discharge will appear after pregnancy with the aura of miscarriage. If the color of menstrual blood is black, it is better to carry out early pregnancy check, if it is determined that there are aura of miscarriage, you can use progesterone to preserve the fetus, and at the same time reasonably supplement vitamin E.