Updated December 29, 2014.

It's not uncommon for people to ask, "What are tonsils?" After all, they don't have a use that immediately comes to mind, like the hand does, for instance. Let's dig into what tonsils are and the function they serve.

There are actually three pairs of tonsils in the throat:

• pharyngeal tonsils (adenoids), which reside behind your nose
• two palatine tonsils (what people are most commonly referring to when they say the word 'tonsils'), which reside on both sides of the back of the throat

• lingual tonsils, which are at the back of the tongue

These specialized organs are part of the lymphatic system and provide our body’s first protective barrier from foreign substances that we inhale or ingest through the nose or mouth. Once trapped in the tonsils, the bacteria or viruses are then transported to lymph nodes where specialized immune cells cluster to fight infection.
A bit contrary to their function the tonsils can also become infected. When examining your tonsils, a physician will usually use your medical history, a physical exam, and in some cases an x-ray (to further examine the adenoids) or blood tests (to determine whether mononucleosis is the cause of tonsil enlargement). Tonsil enlargement is not always considered a problem. However, individuals with enlarged tonsils should be evaluated for the following possible problems related to enlarged tonsils:

• chronic ear infections
• hearing loss
• frequent tonsillitis or sinus infections despite medical treatment
• frequent nose bleeds

• continual mouth-breathing
• abnormal speech or difficulty swallowing
• obstructive sleep apnea

The tonsils can be surgically removed. This is called a tonsillectomy. At one point, physicians removed tonsils after just one or two infections. Due to the risks associated with removing the tonsils, surgeons have become much more conservative. That said, tonsillectomy is frequently performed in the United States and complications are rare.

<sub>Sources:

American Academy of Otolaryngology – Head and Neck Surgery. Tonsils and Adenoids. Accessed on June 4, 2009 from http://www.entnet.org/HealthInformation/tonsilsAdenoids.cfm

MerckMedicus. Enlarged Tonsils and Adenoids. Accessed on June 4, 2009 from www.merckmedicus.com (subscription required)

Schmitt, B.D. Tonsil and Adenoid Surgery. Accessed on June 4, 2009 from www.merckmedicus.com (subscription required)</sub>