Causes of Light and Dark Menstrual Flow

Menstrual bleeding that is light in amount and dark in color may be caused by the following factors: 1. Hormonal imbalance: Imbalances in estrogen and progesterone levels within the endocrine system may lead to decreased menstrual flow and darker coloration. This could be related to ovarian dysfunction, polycystic ovary syndrome (PCOS), or abnormal thyroid function. 2. Intrauterine adhesions: Previous uterine procedures (such as abortion or curettage) may cause adhesions of the endometrium, affecting the outflow of menstrual blood and causing it to remain in the uterine cavity for prolonged periods, resulting in darkened color. 3. Anemia: Iron deficiency in the body may cause reduced menstrual flow and paler menstrual blood. Blood remaining in the uterus after menstruation may oxidize and turn dark. 4. Age-related factors: During early puberty or approaching menopause, fluctuations in hormone levels may cause changes in both menstrual flow and color. 5. Lifestyle factors: Chronic stress, poor diet, excessive weight loss, or intense physical exercise can also affect menstruation. 6. Medical conditions: Certain gynecological diseases, such as uterine fibroids, endometritis, or cervicitis, may also lead to menstrual abnormalities.