Low or inverted t-wave can be seen in normal people, coronary heart disease, cardiomyopathy and so on. T-wave flattening or inversion is common in normal people, although there are abnormalities in the ECG, but there is no organic change in the heart, so there is no need for special treatment. Patients with coronary artery disease have myocardial ischemia, the electrocardiogram may show T-wave flattening or inversion, and the symptoms may be more obvious during the attack of the disease, and it is necessary to improve the coronary artery angiography and other related examinations to clarify the degree of coronary artery stenosis. Patients with myocarditis have myocardial injury and ischemia, and the electrocardiogram may also show flattened or inverted T waves, and the reason for the change in the electrocardiogram may be related to the electrolyte changes at the site of ischemia. T-wave flattening or inversion can be seen in many diseases, patients with obvious symptoms should go to the hospital in a timely manner, under the guidance of the physician to improve the relevant tests to clarify the diagnosis.