Tonsillitis often happens when common viruses cause swelling, also called inflammation, in the tonsils. Bacteria also can cause this condition. Tonsillitis usually affects children between preschool ages and the mid-teenage years. Children can catch germs that lead to tonsillitis when they have close contact with each other.

With tonsillitis, it's common for the tonsils to look swollen and red. They also may have white or yellow patches. Other symptoms can include a sore throat, scratchy or muffled voice, trouble swallowing, bad breath, and fever. The neck may feel painful and stiff. Lymph nodes in the neck may be swollen and tender. The head or stomach may hurt too.

Treatment for tonsillitis mainly depends on its cause. If a virus causes it, rest and at-home care are the only treatments. If bacteria are the cause, antibiotic medicine can help clear the infection. Surgery to remove the tonsils may be used to treat tonsillitis that keeps coming back, lasts a long time or doesn't get better with antibiotics.