Postnasal leakage, also known as postnasal drip syndrome (postnasal drip syndrome), sputum spitting not as possible is due to rhinitis, sinusitis, nasopharyngitis and other diseases are not effectively controlled. 1. Rhinitis: Commonly caused by chronic rhinitis when the allergic organism is exposed to allergens, resulting in congestion of the nasal mucosa, increased secretion of the glands, the emergence of nasal mucus flowing backward into the throat, or the recurrence of sputum spitting not as much as possible. 2. Sinusitis: due to the anatomical factors of the sinus opening complex, resulting in poor drainage of sinus secretions; or sinus inflammation secretion increases so that the nasal mucus flows backward into the throat, appearing repeatedly coughing up sputum. The sputum is not spat out. 3. Chronic nasopharyngitis: commonly seen in chronic inflammation of the mucosa of the nasopharynx, leading to an increase in secretions, flowing into the pharynx, causing mucous phlegm-like secretions spit not exhausted. Therefore, the appearance of postnasal drip is recommended to consult a doctor in time to clarify the diagnosis and carry out targeted treatment.