Coughing while lying down is a more common clinical symptom, mostly seen in reflux pharyngitis and chronic cardiac insufficiency, as follows: 1. Reflux pharyngitis: the most common is the presence of reflux pharyngitis, due to the presence of gastric or esophageal diseases leading to gastroesophageal reflux. This is due to the decrease in esophageal tension when lying down, which leads to more obvious reflux symptoms, and the reflux of gastric contents to the throat will stimulate the cough receptors in the throat, resulting in coughing symptoms. 2. Chronic cardiac insufficiency: In the case of the elderly, this is usually caused by chronic cardiac insufficiency. Due to the presence of chronic cardiac insufficiency, when the patient is lying down the amount of return blood increases, further increasing the load on the heart, so it will lead to increased pulmonary stasis, thus causing cough symptoms. Therefore, coughing while lying down should be diagnosed in a timely manner by improving gastroscopy and cardiac ultrasound.