There are many reasons for lying down at night and coughing seriously, commonly found in cardiac insufficiency, cough variant asthma, gastroesophageal reflux disease and so on. 1. Cardiac insufficiency: cardiac insufficiency can lead to patients lying down because of the sudden increase in the amount of return blood, the heart load increases, aggravate the lungs bruises, and coughing, often accompanied by tightness in the chest, or even dyspnea. 2. Cough variant asthma: a special type of asthma, related to contact with allergens, mainly manifested as irritating dry cough, mostly at night and early morning episodes, without obvious wheezing, shortness of breath and other symptoms. 3. Gastroesophageal Reflux Disease (GERD): This disease is mainly associated with excessive secretion of gastric acid, lying down, acidic reflux may reflux to the throat, irritating the throat and trachea, which leads to increased coughing, and accompanied by acid reflux, heartburn and other symptoms. Lying down at night cough serious can also be seen in other causes, such as nasal secretion reflux stimulation caused by cough, chronic bronchitis, bronchial dilatation and other airway secretions in the position after the change in the flow will also stimulate the mucous membranes caused by coughing, it is recommended that the patient to go to the hospital in a timely manner, to clarify the cause of the disease, and treatment under the guidance of the doctor.