If you have just started your period, it is normal for the blood to be dark. However, if the entire period is black, it is usually not normal. Normally a woman’s menstrual period should be red or dark red in color. When you first get your period, it can be somewhat dark because the blood stays in the uterus for a long time. However, as the volume of menstruation increases and the residence time becomes shorter, it can appear bright red or dark red. Menstrual blood appears black, indicating that the menstrual blood stays in the woman’s uterus for a long time, called stale bleeding, which is a manifestation of menstrual disorders in women and may be caused by uterine cold, gynecological inflammation, fibroids, etc. Women with black menstruation can consult a hospital gynecologist to check and confirm the diagnosis and deal with it accordingly. It is recommended to soak your feet in hot water before going to bed to promote blood circulation, which can make menstrual blood flow more smoothly and restore the color to normal.