The pale color of menstrual blood can be caused by a variety of conditions. For normal healthy women, at the beginning or end of menstruation, due to the low volume of menstrual blood, the amount of fibrinolytic enzymes in menstrual blood is low and not able to act as a clotting agent, resulting in a bright red or light red color of menstrual blood. This cause is normal and is usually nothing to worry about. In addition, anemia, endometrial inflammation and endocrine disorders can also cause the blood color of menstruation to become lighter, and should be actively treated after a clear diagnosis. 1, anemia: anemia causes the color of menstruation to become lighter, mainly due to the reduction of red blood cells, hemoglobin and red blood cell pressure product in the blood, making the blood color lighter, often accompanied by pale, weak symptoms, it is recommended that further blood specialist examination and diagnosis, and actively replenish blood treatment. 2, uterine Endometrial inflammation: In the presence of inflammation of the endometrium, there is often a large amount of exudation, and menstrual blood will be diluted, making the color of menstruation lighter. It is recommended to do diagnostic scraping within 6-12 hours of menstruation to perform pathological tests and further anti-inflammatory treatment according to the test results; 3, endocrine disorders: endocrine disorders can lead to menstrual disorders, manifested by changes in the volume and shade of menstrual blood, which can be diagnosed by going to the hospital for sex hormone testing; 4, other: some tumors in the uterus, such as fibroids, can also lead to light-colored menstrual blood.