Left armpit pain may be caused by folliculitis, sebaceous cysts, breast hyperplasia, etc. Generally, you need to take different medications according to different causes, including antibiotic drugs or non-steroidal anti-inflammatory drugs. 1. Folliculitis: a bacterial infection caused by skin inflammation, early manifestations of redness, swelling, heat and pain, especially when touching the pain is more pronounced, you can take oral antibiotic drugs such as roxithromycin, azithromycin, and with the local use of erythromycin ointment, mupirocin ointment and other applications, to promote the reduction of swelling. 2. Sebaceous cysts: most of them are caused by secondary bacterial infections, which can be taken orally with antibiotics such as levofloxacin and other local medications to promote swelling, and the cysts will be removed if necessary. 3. Breast hyperplasia: If the pain is more obvious, you can take non-steroidal anti-inflammatory drugs, such as ibuprofen, acetaminophen and so on. All of the above medications should be taken under the guidance of a doctor, and should not be used arbitrarily.