The slightest activity is short of breath consider cardiac insufficiency, respiratory diseases, physiological factors. Cardiac insufficiency: due to primary heart disease such as coronary heart disease, cardiomyopathy and other causes of cardiac pressure load or volume load caused by excessive cardiac compensation has developed into a state of decompensation, the heart ejection of blood can not meet the needs of the body, so there will be an activity panting. Respiratory diseases: such as emphysema, pleural effusion, pulmonary heart disease and other causes of lung ventilation function is not good, the state of hypoxia. Physiological factors: for example, in highland areas, excessive obesity or the first recovery from a serious illness can also cause shortness of breath at the first activity. So it is best to go to the hospital to check the specific causes of shortness of breath for treatment.