Being particularly nervous while doing an ECG does not usually cause T-wave changes. The T wave represents the change in electrical potential during ventricular repolarization and is mostly in the same direction as the main QRS wave. When the ventricular repolarization process is abnormal, such as myocardial ischemia or ventricular hypertrophy, T-wave changes are often seen on the ECG. 1. Myocardial ischemia: When myocardial ischemia occurs, the repolarization process will produce changes, and abnormal T waves can appear on the ECG. Coronary ischemia mainly affects the ventricular repolarization process, and the electrocardiogram shows ST-T changes. Ischemic T-wave changes mainly show T-wave flattening, T-wave bi-directionality, and T-wave inversion. Among the T-wave changes, it is of great significance in the diagnosis of myocardial ischemia. Myocardial ischemia ECG changes are not unique to coronary artery disease, but can also be seen in other heart disease and many pathological phenomena, and even healthy people can also appear similar ECG. 2. Ventricular hypertrophy: hypertrophy of the left ventricular wall or the right ventricular wall can cause changes in the repolarization sequence of the ventricular muscle, which is manifested as secondary ST-T changes on the ECG. Nervousness does not usually cause T-wave changes on the ECG, but if T-wave changes are seen on the ECG, professional advice should be sought from a physician.