Difficulty in breathing and chest tightness and shortness of breath while sleeping are generally considered causes of respiratory diseases such as chronic obstructive pulmonary disease and obstructive sleep apnea, cardiovascular diseases such as heart failure, and digestive system diseases such as gastroesophageal reflux. 1. Respiratory diseases: chronic obstructive pulmonary disease, pulmonary heart disease, obstructive sleep apnea hypoventilation syndrome, bronchial asthma, pneumothorax, pleurisy, etc., at night, the vagus nerve excitability increases, which may cause tracheal and bronchial smooth muscle contraction spasm, and at night, it is easy to have an attack, and there is a lack of oxygen, which leads to aggravation of respiratory distress. 2. Cardiovascular diseases: coronary atherosclerotic heart disease, heart valve disease, hypertensive heart disease, etc., easy to cause cardiac insufficiency, the patient rests at night, it will increase the amount of return blood, aggravate the burden on the heart, aggravate the lungs stagnation, leading to telangiectasia, cardiogenic asthma, etc.. 3. Digestive system diseases: resting flat on your back at night can cause gastroesophageal reflux, resulting in food stimulation of the trachea, causing tracheal spasms appearing chest tightness episodes. Difficulty in breathing while sleeping chest tightness may also have other reasons, it is recommended that timely medical treatment, improve the examination under the guidance of the doctor to treat the cause.