The causes of pain in the left breast near the chest include the following: 1. Diseases of the breast itself, whether mastopexy or other occupational diseases, the effects caused by inflammatory diseases of the breast, may cause painful discomfort in this area, mastopexy is directly related to the menstrual cycle. 2. Caused by local trauma, such as this area has ribs, if there is trauma causing If there is a rib fracture, or muscle strain, or hematoma stimulation, there will be significant local pain. 3, the impact of lung disease, such as pneumonia, may stimulate the local pleura causing pain. 4, the impact of heart disease, ischemic heart disease, commonly myocardial infarction, will cause severe pain in this area, patients should seek medical attention in a timely manner.