Patients with hard bumps under the armpit, the common clinical causes are mainly the following: a. Patients with hyperplasia of neurofibroma at the armpit, can appear hard bumps with a hard texture, neurofibroma belongs to benign lesions. When the volume is small, if it does not cause local pain symptoms, the patient can be advised to observe it closely and no special treatment is needed for the time being. If the size of the neurofibroma increases progressively and the patient has painful symptoms in the armpit, surgery may be considered for removal. If there is enlargement of lymph nodes in the armpit, it may also appear as a hard lump with a hard texture. For swollen lymph nodes caused by infection, anti-infection treatment can be intensified to promote faster absorption of the swollen lymph nodes. For lymph node metastasis caused by tumor lesions, resection of the primary tumor plus lymph node dissection, combined with chemotherapy and radiotherapy after surgery, can often achieve certain therapeutic effects.