The main causes of redness, swelling and pain in axillary lumps include the following: 1. It is possible that the swelling and pain are caused by secondary infection of the hair follicles and sebaceous cysts on the skin surface of the armpit, which is more common in clinical practice; 2. Redness, swelling and pain in axillary lumps may also be caused by inflammation of the lymph nodes in the armpit, which is caused by bacterial infection and can lead to swelling of the armpit The swelling appears, and sometimes the serious lymph nodes will become purulent or even break down, and this pain is more intense; 3. The redness and pain of the lumps in the armpit may also be caused by lymphatic tuberculosis in the armpit, and there may be tumors, including lymphoma and metastatic lymph nodes, which can cause these symptoms. In short, if you have painful lumps in the armpit, you should go to the hospital in time to improve the relevant examination, find the exact cause and then take the appropriate treatment.