Pacemaker armpit pain may be caused by overwork, axillary lymphadenitis, myocardial ischemia, etc. It can be relieved by daily recuperation, medication and surgery. 1. Excessive fatigue: heavy physical activity after pacemaker installation leads to excessive arm fatigue, which causes armpit pain. The symptoms of underarm pain can be improved by restricting arm activities, massaging the arm and resting. 2. Axillary lymphadenitis: Infection of the skin in the armpit after pacemaker installation leads to axillary lymphadenitis, which causes armpit pain, and can be treated by applying medicines such as erythromycin ointment. After cleaning the armpits, apply erythromycin ointment as prescribed by the doctor to solve the inflammation, so as to relieve the symptoms of underarm pain. 3. Myocardial ischemia: installing a pacemaker can’t completely improve the symptoms of myocardial ischemia, and insufficient blood supply to the myocardium can lead to underarm pain. You can follow the doctor’s instructions to take aspirin enteric-coated tablets, isosorbide mononitrate tablets and other drugs to stabilize the blood supply to the heart, dilate blood vessels, and if necessary, coronary artery bypass grafting surgery to improve the problem of narrowing of the heart tube, so as to solve the symptoms of underarm pain. Patients with underarm pain symptoms after pacemaker installation should consult a doctor for timely examination and take appropriate treatment according to the doctor’s diagnosis.