Hard lumps in the armpits can develop for a variety of reasons and the cause needs to be treated. They are usually caused by folliculitis, acute cellulitis, breast cancer and other diseases. 1. Folliculitis: If hard lumps in the armpits are caused by folliculitis, it is recommended to use medication under the guidance of a doctor, such as oral erythromycin and topical mupirocin ointment. In addition, you can also use physical therapy, the use of infrared or ultraviolet light irradiation of the infected part of the anti-infection treatment, so as to eliminate the hard lumps in the armpits. 2. Acute cellulitis: If there are hard lumps in the armpits caused by acute cellulitis, it is recommended to use penicillin or cephalosporin antibiotics to eliminate the hard lumps in the armpits under the guidance of the doctor. In addition, symptomatic treatment for patients, if the patient has a high fever, available antipyretic and analgesic drugs. 3. Breast Cancer: If there are hard lumps in the armpit caused by breast cancer, the main treatment is surgery. It is recommended to seek medical treatment in time and choose to undergo surgical treatment such as mastectomy, radical mastectomy, total mastectomy and so on under doctor’s judgment. Therefore, if patients have hard lumps in their armpits, it is recommended to seek medical treatment in time to find out the cause of the disease and treat it actively. In daily life, patients are advised to maintain good living habits and pay attention to skin hygiene. All of the above drugs should be used in accordance with medical advice.