Men often sleep on their stomachs, there may be some adverse effects on the body. Sleeping on the stomach will cause insufficient oxygen saturation, because sleeping on the stomach will make the thoracic movement is limited, so it will lead to bronchodilatation function is reduced, there will be chronic failure of respiratory function or chronic obstruction of respiratory function and other diseases, such as chronic obstructive pulmonary emphysema, chronic pulmonary heart disease, chronic pulmonary hypertension and so on. These conditions will make the arterial oxygen saturation is reduced, carbon dioxide partial pressure is too high, oxygen partial pressure is too low, thus affecting the function of ventilation and ventilation. Men often sleep on their backs, but also on the cardiovascular compression and obstruction, such as the coronary arteries of the heart, such as when sleeping on their backs, will produce pressure on them, and therefore will lead to spasm and contracture of the coronary arteries, thus causing the blood supply function.