It is not normal for women to have blood clots during menstruation because when the blood clots become heavy during menstruation, it will be accompanied by menstrual cramps, which may be caused by insufficient qi and blood in the body, and also accompanied by facial acne, or even dullness of the face. When women suffer from gynecological diseases can also cause blood clots to become heavy during menstruation, and they will be black blood clots, such as cervical erosion, cervical polyps, endometrial cancer, uterine submucosal fibroids, and other gynecological inflammatory diseases. Irregular menstruation can also lead to blood clots during menstruation, such as anxiety, excessive fatigue or poor dietary habits, which can cause endocrine imbalance in the body and thus affect the changes of menstruation. Irregular menstruation should be adjusted in time, otherwise it will cause amenorrhea, leading to infertility, need to go to the hospital for endocrine hormone examination and ultrasound examination.