If a patient has pain over the left chest, he or she needs to be registered to see a relevant department such as thoracic surgery or cardiovascular medicine. This is because if the pain is caused in this area, there is a possibility that pneumothorax, pleural effusion, and infection in the chest cavity may have caused the inflammation of the pleura, which may lead to the above pain symptoms. For such cases, chest X-ray, chest CT and other related examinations can be completed for clarification. If the patient is found to have an internal chest infection, the patient can be effectively treated with antibiotics. If there is a large amount of pneumothorax or pleural effusion, it can be treated symptomatically through closed chest drainage surgery. Of course, if necessary, electrocardiogram, cardiac ultrasound and other related examinations also need to be clarified to be alert to the occurrence of myocardial infarction and other related diseases.