EKG st-segment depression of 0.5 can be seen in normal people or certain heart disease patients. 1. Physiological reasons: most of the EKG st-segment depression below 0.5 is physiological, which can be seen in normal people, the normal is on the isoelectric line, and may be slightly depressed or shifted, which does not need to be dealt with. 2. Pathological reasons: some patients with heart disease, such as coronary heart disease, myocardial ischemia, hypertrophic cardiomyopathy, myocarditis, non-ST-segment elevation myocardial infarction, etc., can have st-segment depression of 0.5 or more, which needs to be combined with medical history, symptoms and other auxiliary tests to determine the diagnosis and actively treat the primary disease. Therefore, st-segment depression of 0.5 on electrocardiogram is normal in most cases, but it can also occur in some cardiac patients, which needs to be analyzed and handled under the guidance of a professional doctor and with the specific situation.