Tonsillitis is inflammation of the tonsils most commonly caused by viral or bacterial infection. Symptoms may include sore throat and fever. When caused by a bacterium belonging to the group A streptococcus, it is typically referred to as strep throat. The overwhelming majority of people recover completely, with or without medication. In 40%, symptoms will resolve in three days, and within one week in 85% of people, regardless of whether streptococcal infection is present or not.