What Are Adenoids?

adenoids. Photo © A.D.A.M.

Question: What Are Adenoids?


The adenoids, also known as pharyngeal tonsils, are two masses of sponge-like tissue that are in the upper portion of the throat and behind the nose in the nasopharynx near the eustachian tubes. Unlike the tonsils, the adenoids are not easily visible and must be examined with special mirrors or scopes by a physician. The adenoids contain lymphocytes, which make up approximately 25% of the circulating white blood cells in the body.

The adenoids and tonsils play an important role in the immune system and fighting infection. During an infection, the adenoids may swell. The adenoids appear to play a more active role in the immune system in children under 3 years of age. After 5, the adenoids tend to become smaller until they are hardly noticeable during teenage years. Researchers think that perhaps as people get older, their immune systems develop other infection fighting methods. Some children may have enlarged adenoids that can result in:

  • snoring and sleep apnea
  • feelings of congestion or a stuffy nose
  • ear problems related to inadequate fluid drainage from the eustachian tubes


Anderson, D.M., Keith, J., Novak, P.D., & Elliot, M.A. (2002). Mosby's Medical, Nursing & Allied Health Dictionary 6th ed. Mosby: St. Louis, Missouri.

Nemours Foundation. All About Adenoids. Accessed on May 20, 2009 from http://kidshealth.org/kid/ill_injure/sick/adenoids.html.

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