Cardiac ST changes are a manifestation of the electrocardiogram, which may indicate the presence of primary or secondary cardiac disease, or may be seen in physiologic conditions. The former is commonly seen in myocardial ischemia, pericarditis, cardiomyopathy, and pulmonary heart disease, while the latter is related to gender, age, and mood. ST-segment changes may be elevated or depressed and are commonly seen in pathologic conditions. ST segment elevation may be caused by myocardial infarction, angina pectoris, cardiomyopathy, pericardial effusion, pulmonary infarction, intracranial hemorrhage, etc. Pathological conditions that may cause ST segment depression include angina pectoris, hypertensive heart disease, aortic coarctation, digitalis or antidepressant. Physiological factors can also cause a slight change in the ST segment, such as tachycardia after exercise, menopause, elderly women, emotional panic and tension, etc. There is no organic disease, and no special treatment is needed. When ST segment changes of the heart occur, it is recommended to go to the cardiology department of the hospital, to clarify the cause, and to carry out appropriate treatment according to the doctor’s instructions.