DefinitionTonsillitis is inflammation (swelling) of the tonsils.See also:Sore throatStrep throatCauses, incidence, and risk factorsThe tonsils are lymph nodes in the back of the mouth and top of the throat. They normally help to filter out bacteria and other microorganisms to prevent infection in the body.They may become so overwhelmed by bacterial or viral infection that they swell and become inflamed, causing tonsillitis. The infection may also be present in the throat and surrounding areas, causing inflammation of the pharynx. The pharynx is in the back of the throat, between the tonsils and the voicebox (larynx). See: PharyngitisTonsillitis is extremely common, particularly in children.SymptomsDifficulty swallowingEar painFever, chillsHeadacheSore throat - lasts longer than 48 hours an