A growth inside the armpit may be an enlarged lymph node in the armpit, a sebaceous cyst or a female paronychia. Depending on the cause, different treatments should be chosen. 1. Enlarged lymph nodes in the armpit: (1) Inflammatory lymph node enlargement: lymph node enlargement caused by inflammation can be treated with anti-inflammatory drugs under the guidance of a doctor, commonly used drugs such as amoxicillin, cephalosporin and so on. Acute axillary lymphadenitis requires the use of antibiotics intravenous infusion, such as ceftriaxone sodium. (2) Tumor lymph node enlargement: generally caused by tumor metastasis, need to find out the primary focus, such as breast cancer axillary metastasis, this type needs surgical treatment as well as postoperative chemotherapy and other comprehensive treatment. 2. Sebaceous cysts: generally there is a black spot on the bag in the armpit, and those without clinical symptoms can be observed without treatment. If the sebaceous cyst infection caused by adhesion to the surrounding tissues, you can go to the regular hospital for surgical resection. 3. Female paratesticular breasts: If the patient is a woman, it is necessary to consider whether it is paratesticular breasts. When there are symptoms such as oversized breasts affecting daily life, pain or lactation, surgery can be performed to remove the breasts. Therefore, when you find a bag growing inside your armpit, you should go to the hospital to find out the cause of the problem in time and have it treated accordingly. The above medicines should be used according to the doctor’s prescription.