Tonsillitis is an inflammation of the tonsils, lumps of lymph tissue found in the throat. In addition to the tonsils which can be clearly seen dangling down in the back of the throat, people also have tonsils near the roof of the mouth known as adenoids, and both can become inflamed. There are a number of causes for tonsillitis, and an assortment of treatment approaches.

The tonsils are designed to assist the immune system. They trap immune invaders in the mouth before they can enter the rest of the body, acting as a first line of defense to prevent infection. This trait can also make them very vulnerable to infection, as they may fight low-level infection on a regular basis, especially in children, because children are often in environments which expose them to a wide range of bacteria and viruses.

Most commonly, bacteria or viruses infect the tonsils, although tonsillitis can also be caused by fungi and parasites. When infected, the tonsils start to swell, and they may develop white patches or a pus-like discharge. The patient usually has a sore throat, bad breath, and a feeling of general malaise. In some cases, the tonsils become so inflamed that it is difficult to breathe, or the patient has trouble sleeping soundly.

A doctor can diagnose tonsillitis by looking into the patient's mouth and observing that the tissue is obviously inflamed. The doctor may also swab the tonsils for the purpose of preparing a culture to see what has caused the infection. Historically, the response to tonsillitis was surgery to remove the tissue. This is not as common today, except in cases of chronic or very severe tonsillitis. Instead, the patient is given pain management medications and antibiotics, if the infection can be treated with antibiotics.

With basic treatment, tonsillitis can clear up in a week or so. Patients sometimes find that saltwater gargles speed the recovery process and ease pain, and they may find their diets restricted to soft or liquid foods when the tonsils are extremely swollen. After recovering from a bout of tonsillitis, the patient may never experience problems again, or it may recur. If multiple recurrences appear or the tonsillitis becomes debilitating, surgery will be recommended.

The organisms which cause tonsillitis are contagious, and they can be passed from person to person. People should observe basic sanitation such as handwashing and not sharing eating dishes to avoid spreading diseases of all kinds, including those which cause infections of the tonsils, and people with active infections should be encouraged to cover their mouths while coughing, and to wash their hands regularly so that they do not pass the infectious agents on.