If the ECG shows ST-segment depression, it is usually a change in ECG vectorology, which has both physiological and pathological causes. Physiological factors, such as excessive stress, anxiety, poor rest and sleep, heavy alcohol consumption, smoking, strong tea and coffee, or emotional stress, may cause clinical symptoms of ST-segment depression on the ECG. For pathological factors, ST-segment depression is common in cardiogenic diseases, such as coronary artery disease, unstable angina, acute myocarditis, acute pericarditis, or malignant arrhythmia, heart failure, etc. In addition, for endocrine metabolic diseases and ionic disorders, these conditions may also lead to clinical symptoms of ST-segment depression on the ECG.