Phlegm with a foreign body sensation in the throat may be caused by chronic pharyngitis, reflux pharyngitis, postnasal drip syndrome and other diseases. 1. Chronic pharyngitis: chronic inflammation of the pharyngeal mucosa, submucosa and lymphatic tissue. There may be foreign body sensation, burning sensation, itchy sensation, irritation in the throat, etc. The posterior wall of the pharynx is often stimulated by more viscous secretions, and more frequent irritating cough occurs in the morning. 2. Reflux pharyngitis: gastric contents reflux into the throat, irritating the mucous membrane of the throat, resulting in discomfort in the throat, foreign body sensation, phlegm, repeated throat clearing and other discomforts. 3. Postnasal drip syndrome: It refers to the reflux of nasal inflammatory secretion from patients with rhinitis and sinusitis, which flows into the nasopharynx, oropharynx and laryngopharynx through the posterior nostril, causing irritation to the mucous membrane of the pharynx and triggering discomfort in the pharynx. This causes irritation to the mucous membrane of the pharynx, leading to discomfort in the pharynx, resulting in the symptoms of phlegm and a foreign body sensation in the throat. When the symptoms of phlegm and foreign body sensation in the throat occur, it is recommended to consult a hospital for a clear diagnosis and treatment.