Left arm pain needs to choose the appropriate department according to the nature of arm pain, accompanying symptoms, medical history, etc. Consider visiting cardiology, vascular surgery, orthopedics and so on. 1. Cardiology: If left arm pain occurs and is accompanied by symptoms such as chest tightness, palpitations and shortness of breath, it may be myocardial infarction, so it is recommended to consult the cardiology department. 2. Vascular Surgery: If left arm pain occurs at night, sometimes accompanied by numbness, it may be upper extremity venous thrombosis. It is recommended to hang up with the Department of Vascular Surgery and do ultrasound examination of the upper extremity blood vessels and other vascular related examinations. 3. Orthopedics: Left arm pain accompanied by limited movement, stiffness, etc., may be caused by shoulder joint disease and cervical spondylosis, it is recommended to hang up orthopedics. When left arm pain occurs, it is recommended to consult a doctor in time, follow the doctor’s instructions to choose the appropriate examination method, clarify the cause with the help of the doctor, and carry out targeted treatment or therapy.