The fact that the menstrual flow is particularly low on the second day of menstruation may be due to the fact that most of the uterine lining has already been shed, or it may be due to early onset ovarian insufficiency, uterine adhesions, and other disorders. 1. Physiological factors: some women shed most of the endometrium on the first day of menstruation, which can lead to low menstrual flow on the second day of menstruation. 2. Early onset ovarian insufficiency: Early onset ovarian insufficiency is caused by chromosomal abnormalities, autoimmune diseases, viral infections and other factors. The patient will have scanty menstruation, amenorrhea, vaginal dryness and other symptoms, which will lead to the phenomenon that the patient’s menstruation is particularly low on the second day of menstruation. 3. Uterine adhesion: Uterine adhesion is considered to be caused by endometrial trauma, infection, heredity and other factors. Patients mainly show symptoms of reduced menstruation, amenorrhea, cyclic abdominal pain, etc., which will lead to the symptoms of particularly low menstruation on the second day of menstruation. When the patient has the symptom of particularly low menstruation on the second day, it may be caused by physiological factors and no treatment is needed. If it is caused by a disease, it is recommended that the patient consult a doctor in time to identify the cause of the disease and follow the doctor’s instructions for treatment.