Painful armpit lumps are often due to a swollen axillary lymph node under the armpit. This is usually a sign that the body is fighting an infection, but it can sometimes indicate cancer.

A swollen lymph node in the armpit may be a sign of a bacterial or ... for more than 2 weeks or worsens after this time the lump feels hard or does not move when a person touches it there is ...

Less commonly, the pain—referred to as axillary pain—may be due to an autoimmune or arterial disease, nerve compression, and malignancies like breast cancer.The diagnosis of armpit pain may involve ...