Causes of pain in the armpit near the breast area may include the following: 1. Swollen lymph nodes in the armpit. When there is an inflammatory reaction around the armpit, local swelling of the lymph nodes will occur, and when the swollen lymph nodes are pressed, there will be significant pain. 2. Caused by the parammary gland tissue in the armpit, similar to the reaction of mastopexy. The parammary gland tissue, like the normal breast tissue, can be painful when touched, especially before the onset of menstruation. 3. caused by local lesions that are not related to breast disease, such as local inflammatory lesions, sebaceous cyst infection, folliculitis, and even skin diseases including herpes zoster. 4. painful manifestations caused by deep-seated diseases, such as patients suffering from pneumonia or pleural effusion, can also have painful reactions when touched locally There will also be painful reactions when touching the local area.