Tonsillitis refers to the inflammation of the pharyngeal tonsils and is the primary cause of sore throats. Your tonsils are a pair of small almond-shaped organs located on each side of your throat, behind and above the tongue. They function together with another set of organs called the adenoids. Although the adenoids are similar to the tonsils, they can be found in the upper portion of the throat behind the nose and cannot be seen.
The tonsils and adenoids are seen as the first line of defense against respiratory infections that enter the body through the nose, mouth and throat. The inflammation of the tonsils may involve other areas of the back of the throat including the adenoids and the lingual tonsils (areas of tonsil tissue at the back of the tongue).