When men have chest pain, the first thing that should be clarified is whether the pain is unilateral or bilateral, and whether it is chest pain or intra-thoracic pain. It is also important to understand if there is any relationship between chest pain when it comes to strenuous activity, and if it is muscle soreness caused by excessive movement of the pectoralis major muscle due to strenuous activity. If the patient is suffering from chest pain on the left side and the patient is older, you can consider whether it is a case of coronary heart disease. If the patient is accompanied by chest pain when breathing, you need to rule out whether it is the cause of pleurisy. If the patient has very severe pain on one side of the chest, it cannot be ruled out if there is intercostal neuralgia, intercostal neuritis, or herpes zoster. The specific cause should be seen in cardiovascular medicine, thoracic surgery or respiratory medicine, and relevant tests should be performed if necessary, and most of them can clarify the diagnosis. If the cause cannot be identified by any of the above departments, it cannot be completely ruled out that the chest pain is caused by a relatively rare male breast disease, so go to the appropriate department if necessary.