Pain under the right breast when wearing underwear may be inappropriate underwear, breast hyperplasia, mastitis, and so on. The reason is different, the treatment method is also different. 1. Inappropriate underwear: wearing underwear on the edge of the breast pain may be related to the underwear material, when the underwear quality is poor, the size is not appropriate, it will stimulate the skin around the breast, can cause a wear underwear on the edge of the breast pain. At this time, you can change the right underwear to relieve the symptoms. 2. Mammary gland hyperplasia: due to endocrine disorders, hormone imbalance, the structure of the breast tissue is disordered, resulting in the hyperplasia of various parts of the breast, the clinical manifestation of breast pain, nodules or lumps and other symptoms, can appear to wear underwear on the edge of the breast pain, can be under the guidance of the doctor to take medication, such as Xiao Jin Pills. 3. Mastitis: caused by acute suppurative infection of the mammary gland, often occurring in postpartum breastfeeding women, clinical breast swelling, pain, burning sensation and other symptoms, which can lead to a breast edge pain when wearing underwear, this time the patient needs to comply with the doctor’s instructions to use penicillin and other drugs for treatment. 4. Breast cancer: usually associated with radiation, excessive stress, heredity and other factors, the disease becomes a malignant tumor with malignant proliferation of the breast epithelium, and some patients may have symptoms of breast pain. Patients need to receive comprehensive treatment mainly based on surgical treatment under the guidance of doctors. If there is pain under the right breast when wearing underwear, you should go to the regular hospital in time to avoid delay. The use of drugs needs to be under the guidance of doctors.