Armpit bumps may be caused by folliculitis, paronychia, lymphoma and other conditions. 1. Folliculitis: usually due to bacterial and other pathogenic infections, may also be due to excessive sweating, wearing tight clothing, skin trauma and other conditions, and also with the body’s immune system, long-term use of glucocorticoids, obesity, sedentary and other factors. Patients often appear to hair follicles as the center of the red papules, and female patients are more frequent in the armpit or groin area, which can appear in the armpit pimples. 2. Associate breasts: usually due to congenital developmental abnormalities, and female breastfeeding, pregnancy, etc., hormonal changes in the body, can also induce associate breasts. Generally, patients will have swelling or bulging in the axilla or underarm, and patients may also have pain, enlargement, or even lactation symptoms after being affected by sex hormones. 3. Lymphoma: the pathogenesis and etiology are not completely clear, and it is mostly considered to be related to infection, immunity, heredity, occupation, environment and other factors. Lymphoma patients often appear painless neck or supraclavicular lymph nodes progressive enlargement, and some patients may also appear axillary and inguinal lymph node enlargement, which may be manifested as axillary pimples. Armpit lumps may also be caused by other reasons, it is recommended that when the phenomenon of armpit lumps occurs, the cause of the disease is clarified in a timely manner, under the guidance of the doctor to take targeted treatment.