The phlegm in the stomach is considered to be caused by bronchitis, reflux gastritis and other reasons. 1. Bronchitis: bronchitis can appear cough, cough sputum, mucopurulent sputum and other symptoms, if not actively treated or phlegm symptoms are obvious, can be manifested as phlegm in the stomach phenomenon. 2. Reflux Gastritis: Reflux gastritis causes gastric acid to reflux, resulting in mucosal edema in the throat, causing a foreign body sensation, which can be manifested as phlegm in the stomach. When the symptoms of phlegm in the stomach, it is recommended to go to the hospital in a timely manner, under the guidance of a professional doctor to clarify the cause of the disease, and standardized treatment, to avoid aggravation of the condition, which will have an adverse effect on the body.