Coughing while lying down is mostly due to the following reasons: first, gastroesophageal reflux, gastroesophageal reflux patients lie down after the reflux of gastric juice to the trachea, causing coughing aggravation; second, cardiac insufficiency, cardiac insufficiency patients lie down after the increase in the amount of cardiac blood return, causing cardiac insufficiency aggravation, causing pulmonary stasis, causing coughing more obvious; third, pulmonary reasons, lung disease caused by lung function decline, lie down After lying down, the diaphragm rises up, causing a further decline in lung function, which stimulates coughing. Some lung diseases, such as bronchial foreign bodies and lung tumors, can cause increased bronchial irritation and coughing due to the effects of body position. Therefore, if the patient often lies down with a strong cough he should go to the hospital for further examination to clarify the cause.