(HealthDay News) -- Tonsillitis occurs when the tonsils become infected by bacteria or a virus, which causes them to become inflamed and painful.

Here are common symptoms of tonsillitis, courtesy of the U.S. National Library of Medicine:

• Difficult or painful swallowing.
• Pain in the ears and/or jaw.
• Fever, headache, and chills.
• Very sore throat that lasts longer than 48 hours.
• Loss of, or changes in, one's voice.