Night sleep throat itchy phlegm during the day but nothing, may be suffering from reflux pharyngitis, bronchitis, post-nasal drip syndrome and other diseases caused. 1. Reflux pharyngitis: During the day, people are in an upright position, and gravity causes food to flow downward without discomfort. At night, stomach contents reflux to the throat, stimulating mucosal inflammatory reaction, appearing throat itching with phlegm. 2. Bronchitis: some patients have increased vagus nerve excitability at night, and the ability of airway phlegm expulsion decreases due to inflammatory reaction, so there is an itchy throat with phlegm at night, but nothing happens during the day. 3. Postnasal drip syndrome: If you suffer from chronic rhinitis, chronic sinusitis and other diseases, it may induce postnasal drip syndrome, resulting in increased nasal secretions. When sleeping at night, it may lead to snot flowing into the throat, causing irritation to the mucous membrane of the throat, and the symptoms of itchy throat at night and phlegm during the day are fine. Patients are also prone to symptoms such as frequent throat clearing. If you have an itchy throat at night and are fine during the day, it is recommended that you go to the hospital for a checkup to determine the cause of the problem.