Doing ECG with Q wave may be caused by obesity, or it may be caused by cardiomyopathy, myocardial infarction and other diseases. 1. Obesity: because obesity can lead to changes in the position of the heart to a certain extent, the diaphragm uplift occurs, so it is easy to have Q wave when doing ECG examination. 2. Cardiomyopathy: the etiology of this disease is not clear, it may be related to genetics, viral infection, nutrient deficiency, poisoning, amyloidosis, tachycardia, pregnancy and other reasons. Examination may reveal the presence of pathologic Q waves, and patients may have symptoms such as edema and shortness of breath. 3. Myocardial infarction: the occurrence of this disease is related to the increase of myocardial oxygen consumption, insufficient myocardial oxygen supply, and the decrease of myocardial blood perfusion. It can be triggered by factors such as strenuous exercise, overeating, emotional fluctuations, etc., leading to symptoms such as palpitations, shortness of breath, fatigue, pain in the precordial region, etc. Q waves can be seen in ECG examination. Besides, it can also be considered to be caused by coronary heart disease, myocarditis, emphysema and other diseases. If the Q wave on the ECG is excluded as a result of physiological factors, further examination is needed to clarify the specific cause.