There is a cyst under the armpit broken should be actively consult the doctor, give disinfection, prevent infection, if necessary, surgical treatment. 1. Prevent infection: when a cyst under the armpit is broken, there is a possibility of infection, which can be sterilized with iodophor and then bandaged, and change the medicine regularly. To prevent infection, antibiotics such as amoxicillin and cefaclor can be taken. 2. Surgical treatment: if the cyst is large, due to trauma breakage, can be directly surgical resection; such as due to inflammation and infection, abscess breakage, can be surgical incision and drainage, and regular medication change treatment. After out are recommended to take amoxicillin and other antibiotics to prevent infection. Patients with ruptured cysts under the armpit should actively seek medical attention, patients should not use their own medication, but should be treated in accordance with the norms under the guidance of the physician’s interview.