Breast pain after ten days of menstruation may be caused by ovulation, mastitis, breast hyperplasia and other reasons. 1. Ovulation: Ovulation occurs about 14-15 days before the onset of menstruation, and menstruation for ten days may be in the ovulation period, during which ovulation occurs due to fluctuations in the level of hormones in the body, symptoms such as ovulation bleeding, breast pain, and breast pain, breast pain in the ovulation period lasts for a short time and the symptoms are relatively mild, and generally do not require special treatment. 2. Mastitis: Mastitis may be caused by acute suppurative infections, which will cause breast pain, local redness, swelling, fever and other symptoms, and can be treated by using antibiotics such as penicillin or incision and drainage of breast abscesses. 3. Breast Hyperplasia: It may be caused by endocrine function disorders, and may present symptoms such as breast pain, breast lumps, etc., which can be relieved by surgical treatment. Therefore, patients with breast pain after ten days of menstruation should go to the hospital as soon as possible and actively cooperate with the doctor for symptomatic treatment.