Clinical manifestations of left-sided chest tightness and pain are seen to be caused by many causes. It is mainly seen in the following factors: respiratory diseases are seen in the inflammation of some pathogens, such as pneumonia caused by Mycoplasma pneumoniae pneumonia, Mycobacterium tuberculosis, Staphylococcus aureus, Klebsiella and other infections. Also due to trauma that ruptures the pleural cavity, resulting in pneumothorax, or even mediastinal emphysema, combined with infections such as hemopneumothorax and pus pneumothorax. Also seen in intercostal neuritis causing intercostal neuralgia, pleurisy, and also in cardiovascular system diseases, such as angina pectoris and myocardial infarction caused by having coronary heart disease.