A lot of blood clots on your period may be normal, but it can also be caused by diseases such as endometrial polyps, fibroids, and adenomyosis. 1. Normal situation: the formation of menstruation is related to the endometrial stripping caused by changes in the level of sex hormones in the body. And when the body’s sex hormone levels change greatly, prompting a large piece of endometrial stripping, it will occur to the phenomenon of a lot of blood clots, as long as the total amount of blood does not cause anemia, is a normal situation. 2. Endometrial polyps: the cause of the disease is not clear, may be related to high estrogen levels, inflammatory stimulation. Typical symptoms of patients include bleeding between menstrual periods, excessive menstrual flow, vaginal discharge of foul-smelling bloody secretions, etc. Some patients may have a lot of blood clots due to excessive menstrual flow and retention. 3. Uterine fibroids: the cause of this disease is not clear, but it is considered to be related to heredity and sex hormone level. Some patients do not have obvious symptoms, but some of them may have increased menstrual flow, pressure symptoms, etc. Therefore, patients with uterine fibroids may also have a lot of blood clots due to increased menstrual flow. 4. Uterine adenomyosis: the cause of this disease is not clear, which may be related to uterine operation, endometrial inflammation and so on. Typical symptoms of patients include increased menstrual flow, prolonged menstrual period, etc., which can also be manifested as the phenomenon of having a lot of blood clots during menstruation. It is recommended that people who have a lot of blood clots during their period and other uncomfortable symptoms should consult a doctor in a timely manner.