Tonsillitis vs. strep throat: What's the difference?

Tonsillitis is an inflammation of the tonsils caused by a viral or bacterial infection. Many different viruses and bacteria can cause tonsillitis. When tonsillitis is due to a specific type of bacteria — group A streptococci — the illness is also referred to as strep throat.

Bacterial tonsillitis, including strep throat, is treated with antibiotics. However, most cases of tonsillitis are caused by viral infections, which do not respond to antibiotics. In such cases, treatment is directed at relieving the signs and symptoms of tonsillitis.