For female patients who have left-sided chest pain: 1. Consider high-risk chest pain. For example, acute coronary syndrome, pulmonary embolism, aortic coarctation or tension pneumothorax, which have low incidence but high mortality. 2. Consider cardiogenic diseases. For example, coronary artery disease, unstable angina, myocarditis, various heart valve diseases, rheumatic heart disease, hypertrophic obstructive cardiomyopathy. 3, respiratory system diseases, such as massive lung infection on the left side, pleurisy, pleural effusion. 4, for diseases of the chest wall. For example, intercostal neuralgia, chest wall tumor, will also have pain on the left side of the chest. 5, some rare diseases, such as herpes zoster and other conditions. 6, women who have lobular hyperplasia of the breast, acute mastitis, breast tumor and other conditions, the left side of the chest will also have pain.