Hello, in general, the causes of acute pharyngitis are: 1. Decreased general resistance, such as fatigue or excessive drinking. 2. It involves nasal diseases. 3. Tonsil inflammation. 4. Poor living environment; There are irritating substances in the working environment, such as tanneries and cigarette factories; Toxic chemicals, including chlorine, ammonia and other irritants. 5. Precursor symptoms of upper respiratory tract infection. 6. Chronic systemic diseases lead to decreased respiratory resistance. 7. Allergic factors. 8. Gastroesophageal reflux.