The common causes of fleshy bumps in the armpits are: 1. Folliculitis. It is mainly caused by local hair follicle infection, early mainly local itching, further development, will be accompanied by varying degrees of redness, swelling, heat, pain. It is recommended to use local mupirocin ointment for application and take oral amoxicillin capsules and forsythia pills for treatment. 2. sebaceous cysts. It is mainly caused by the local hair follicle blockage, there will be black depressions on the surface, inflammation will appear red, swollen and painful, mainly surgical removal. 3, lymph node inflammation. If a woman has an infection in her body, the infection will invade the lymph nodes in the armpit, and the lymph nodes will be swollen and form bumps protruding from the skin. 4. Breast cancer. Patients with breast cancer are prone to ipsilateral lymph node metastasis, which mainly manifests as swollen lymph nodes and pain.