Sudden sore throat may be caused by acute epiglottitis, acute tonsillitis, acute pharyngitis and so on. 1. Acute epiglottitis: If you suffer from acute epiglottitis, you may experience a sudden sore throat, and the pain worsens when you swallow. 2. Acute tonsillitis: If you have a sudden sore throat and localized tonsils are swollen and congested, you can consider it as acute tonsillitis. 3. Acute pharyngitis: Acute pharyngitis, which can cause sudden throat pain, can also be accompanied by dry itching, foreign body sensation, cough and other symptoms. It is recommended that people with sudden sore throat go to regular hospitals in time to clarify the cause of the disease and standardize the treatment under the guidance of the doctor to avoid delaying the condition.