Painful swallowing can be caused by tonsillitis, acute pharyngitis and acute epiglottitis. 1. Tonsillitis: Tonsillitis is an infectious disease caused by pathogenic microorganisms, patients will have symptoms of sore throat, pain is significant when swallowing, the causes include infectious factors, immune factors and acute inflammation of neighboring organs. 2. Acute pharyngitis: acute pharyngitis is an acute inflammation of the mucous membrane and surrounding tissues in the pharynx, the cause of which is related to viral and bacterial infections and environmental factors, and patients will experience dry and itchy throat, sore throat and other symptoms. 3. Acute epiglottitis: Acute epiglottitis is an acute inflammatory lesion of the epiglottis and its surrounding tissues, the cause of which is related to infections and metabolic reactions, and the patient will experience symptoms such as severe sore throat and difficulty in swallowing, and the pain may worsen when swallowing saliva. There are more causes of painful gagging, and patients are advised to seek medical examination for a clear diagnosis.