What causes phlegm that cannot be completely coughed out at the connection between the nose and throat, and what should be done?

Generally, the sensation of phlegm that cannot be fully expelled at the junction of the nose and throat may be caused by environmental factors, dietary factors, chronic rhinitis, chronic pharyngitis, or postnasal drip syndrome. Treatment may include general care measures and medications under a doctor's guidance. If symptoms persist, timely medical consultation is recommended. The detailed explanation is as follows:

1. Environmental Factors

When staying in a dry, dusty, or pungent-odored environment, the nasal and nasopharyngeal mucosa may be irritated, causing increased mucus secretion to protect the respiratory tract, resulting in a persistent phlegm sensation at this area. Wearing a mask can help reduce respiratory irritation from adverse environmental conditions, and using an air purifier can improve indoor air quality.

2. Dietary Factors

Consuming excessive spicy, greasy, or sweet foods or alcohol can irritate the nasopharyngeal mucosa and increase secretion production. It is important to adjust dietary habits by reducing intake of these foods and increasing consumption of vitamin-rich foods such as vegetables and fruits. A light and regular diet is recommended, avoiding overeating.

3. Chronic Rhinitis

Chronic rhinitis often develops from repeated episodes of acute rhinitis, nasal structural abnormalities, or long-term inhalation of harmful gases. The nasal mucosa remains inflamed for a prolonged period, producing excessive secretions that may drain backward into the nasopharynx, causing persistent phlegm sensation at the junction of the nose and throat. Symptoms may include nasal congestion, runny nose, and reduced sense of smell. Medications such as budesonide nasal spray, Bi Yan Kang tablets, and eucalyptus oil soft capsules may be used under medical guidance for treatment.

4. Chronic Pharyngitis

Chronic pharyngitis is usually caused by repeated episodes of acute pharyngitis, chronic inflammation from nasal diseases and respiratory conditions, chronic mouth breathing, excessive smoking and alcohol consumption, or exposure to dust and harmful gases. Inflammatory stimulation causes hyperplasia and thickening of the pharyngeal mucosa and submucosal tissues, with increased secretory activity, leading to accumulation of excess phlegm in the nasopharynx. Symptoms may include a foreign body sensation in the throat and dryness. Medications such as throat tablets, Qing Hou Li Yan granules, and compound borax mouthwash may be used as directed by a physician.

5. Postnasal Drip Syndrome

Postnasal drip syndrome is usually caused by inflammatory nasal conditions, nasal polyps, or improper medication use. Excessive nasal secretions drain backward into the nasopharynx and throat, causing a persistent sensation of phlegm that cannot be fully expelled. Symptoms may include cough, nasal congestion, and runny nose. Treatment should target the underlying nasal condition—for example, in cases of sinusitis, medications such as clarithromycin extended-release tablets, mometasone furoate nasal spray, and oral sinusitis medication may be prescribed by a doctor.

In daily life, it is recommended to strengthen physical exercise, enhance physical resistance, and prevent respiratory infections such as the common cold. Maintain nasal hygiene by using saline nasal irrigation. Pay attention to oral hygiene by brushing teeth in the morning and evening and rinsing the mouth after meals.