Tonsillitis is an infection of the tonsils. The tonsils are two small glands found at the back of the throat behind the tongue. The function of these glands is not entirely clear, but research suggests that they help to fight infections.
The main symptom of tonsillitis is a sore throat. There may be several other symptoms such as coughing, headaches and a fever.
Tonsillitis can be caused by either a virus or bacteria, although most cases are viral. The incubation period (the time between picking up the infection and symptoms starting to appear) is usually two to four days.
Tonsillitis can spread from person to person through hand contact (then touching your mouth with contaminated hands), breathing in the airborne droplets after someone with tonsillitis has sneezed or sharing the utensils or toothbrush of an infected person.