Leg pain during menstruation is a special dysmenorrhea symptom that occurs mainly due to the following reasons: 1) the pelvic tissues are congested during menstruation, which may stimulate the nerves and cause pain in the lower limbs; 2) if the female uterus is anatomically altered in the pelvic cavity, it may also cause reflex pain in the lower limbs during menstruation due to the congestion of the uterus and the pelvic tissues, which stimulates the pelvic wall; 3) women who have a birth control ring placed in the uterus may have significant pain in the lower limbs during menstruation. 3. Women who have a birth control ring placed in the uterine cavity may experience significant lower limb pain during menstruation, which is mainly related to the stimulating effect of the ring on the uterine wall; 4. Chronic blood loss during menstruation can affect the hematopoietic system of the bone marrow, which may also cause lower limb pain.