Tonsils are tissue on both sides of the back of the throat that help the body fight infection. They trap bacteria and viruses entering through the throat and produce antibodies to fight infection.Tonsillitis means the tonsils are infected. Tonsils become infected by bacteria or viruses, which causes them to swell.
Frequent or recurrent tonsillitis is generally defined as:
More than 7 episodes in 1 year
More than 5 episodes a year during a 2-year period
More than 3 episodes a year during a 3-year period
Tonsillitis may or may not be contagious, depending on the cause. If the cause is viral or bacterial, it is usually contagious.