Unspeakable discomfort in the left chest, usually suggests that it may be a problem in the lungs or the heart, which is common in the following aspects: 1, lung disease: lung infection, lung tumors are common, due to infection or tumor lesions involved in the pleura, stimulation of the nerves in the pleura can cause pain or uncomfortable feeling, and need to further improve the CT examination of lungs to make it clear; 2, cardiac problems: angina pectoris, myocardial bridging lesions are common, angina pectoris With coronary artery atherosclerosis leads to blood vessel narrowing, or coronary artery vascular spasm, thus causing myocardial ischemia, hypoxia related, can be manifested as chest tightness, chest pain and chest discomfort. Myocardial bridging lesions are caused by increased myocardial contractility, which pressurizes the coronary vessels traveling within the myocardium, thus affecting myocardial blood supply. Heart problems are mainly clarified by electrocardiogram, cardiac ultrasound and coronary angiography.