There are several cases of pain on the left side of the heart fossa: first, esophagitis due to acid reflux, because the anatomical structure of the esophagus is biased to the left side, acid reflux will lead to burning-like pain on the left side of the chest; second, it may be a lesion of the left chest wall, chest wall muscles and ribs can also lead to pain around the left side of the heart fossa when the lesion is clear; third, it may be pleural and pulmonary lesions, tuberculous pleurisy and pulmonary tuberculosis can lead to left-sided chest pain; fourth, it may be due to myocardial ischemia caused by coronary artery stenosis or occlusion, which will lead to radiating pain on the left side, the most serious case; fifth, it may also be chest pain due to anxiety, where the patient has the feeling of being compressed. It is recommended that it is best to go to the hospital to see a doctor for an examination and, if necessary, a chest fluoroscopy or a chest X-ray to exclude lung disease, and only a clear diagnosis of the cause can be targeted at the patient.