Hidden pain in the right side under the armpit may be due to skin infection, breast enlargement, axillary lymphadenitis, and so on. The medications used for different causes are different. 1. Skin infections: boils and cellulitis in the armpits can cause pain in the right armpit, accompanied by localized redness and swelling of the skin and increased skin temperature. At this time, you can take amoxicillin, cefaclor and other antibiotic treatment, after the inflammation subsides, the symptoms can be improved. 2. Breast hyperplasia: due to the high level of estrogen in the body, women may have breast hyperplasia, causing vague pain in the right armpit, usually no treatment, just need to observe. If the symptoms are particularly obvious, you can take oral pills, ibuprofen and other relief, combined with hot compresses, massage, and avoid exertion. 3. Axillary lymphadenitis: When mumps, tonsillitis, sinusitis and other head and neck infections are found, it is easier to have swollen axillary lymph nodes. When fever is obvious, ibuprofen can be used to reduce fever, and antibiotics such as cefixime can be used to fight inflammation. Hidden pain in the right armpit may be due to other reasons, such as rib fracture caused by trauma. It is recommended to consult a doctor in time to find out the cause, and take scientific and effective treatment according to the cause of the disease. The above medication is in accordance with the doctor’s prescription.