Aunt’s blood refers to menstrual blood. Dark red menstrual blood refers to menstrual blood that is dark red in color. There are many reasons for this, which may be caused by normal physiological symptoms, declining ovarian function, improper personal care during menstruation, etc. Patients should observe for a period of time, and if the symptoms don’t disappear, they should consult a doctor for a clear diagnosis. 1. Normal physiological conditions: menstruation is formed by cyclic shedding of the endometrium, menstrual blood stays in the uterus for a longer period of time, and the blood is oxidized to form a dark red color, at this time the menstrual blood shows a dark red color, which is a normal phenomenon, and the patient does not need to be overly concerned about it. 2. Ovarian hypoplasia: When ovarian hypoplasia occurs in women, there will be abnormal menstruation, low menstrual flow, and dark red color of menstruation. 3. Improper care during menstruation: The patient’s menstrual blood may be dark red in color due to inattention to rest, overwork, and lack of attention to warmth during menstruation. There may also be other reasons, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or treatment.