These are the pair of rounded tissues on either side of the back of the throat. The tonsils help fight infections, but they can become infected themselves.
Acute tonsillitis goes along with many throat infections, including strep throat.
It is most common in children between the ages of 5 and 10. It usually lasts 4 to 6 days. However, tonsillitis can become a chronic or recurring problem in children or adults. This is especially important for children. Cases of strep throat require antibiotics.