Taking antiemetic drugs generally does not cause breast pain, breast pain may be a normal physiological phenomenon caused by hormonal changes in the female body before and after menstruation, or it may be caused by breast hyperplasia, mastitis, breast cancer and other pathological reasons. 1. Normal physiological phenomenon: some women may have transient mild breast pain before and after menstruation, which can be relieved after menstruation. This is caused by hormonal changes in women’s body, which is a normal physiological phenomenon and does not require special treatment. 2. Breast Hyperplasia: It is mainly due to the abnormal secretion of sex hormones in the patient’s body caused by glandular hyperplasia, which leads to breast swelling and discomfort. The pain is cyclical and is mainly related to menstruation, with swelling and pain in the premenstrual period and relief after menstruation, which can be confirmed by ultrasound examination. 3. Mastitis: It is caused by inflammation caused by infection and stimulation of nerves. In addition to the symptoms of breast pain, it is also accompanied by chills, high fever, breast swelling and even abscess, and it is mostly found in breastfeeding female patients. 4. Breast Cancer: Breast cancer lump or lesion will have breast pain when it invades the local skin of the breast, which is mainly manifested as persistent or paroxysmal stabbing pain or dull pain in the breast. If breast pain occurs for a long time, don’t judge it by yourself, but consult a doctor in time and take corresponding treatment under the doctor’s guidance, so as to avoid delaying the condition.