Tonsillitis is an infection that causes the tonsils, two small glands located at the back of the throat, to become swollen and inflamed. This condition can be caused by viruses or bacteria, leading to symptoms like a sore throat, difficulty swallowing, and fever. Children are more likely to get tonsillitis, but it can affect people of all ages. Treatment for tonsillitis often includes rest, fluids, and over-the-counter pain relievers. In some cases, especially if caused by bacteria like Streptococcus, antibiotics may be prescribed. If tonsillitis occurs frequently, a doctor might recommend removing the tonsils through a procedure called a tonsillectomy.