Tonsillitis is an inflammation or infection of the tonsils.
The body has two sets, or pairs, of tonsils. The palatine tonsils can be seen at the back of the throat. The lingual tonsils are at the back of the tongue and cannot be seen by looking in the mouth. Tonsillitis usually means the inflammation or infection of the palatine tonsils. But sometimes the infection can involve the lingual tonsils and lymph nodes in the back of the throat.
Common causes of acute tonsillitis may include:
Subacute tonsillitis is most commonly caused by actinomyces, a normal mouth bacterium that can cause infection.
In chronic tonsillitis, there is a long-standing infection that is almost always bacterial.