Adenoids are areas of lymphatic tissue found at the back of the nose and top of the throat. In some people, most commonly children, these areas can become enlarged and may cause upper respiratory problems. Lymphatic tissue is part of the immune system. It helps fight off bacteria and viruses that try to enter the body. When such microbes enter the body through the mouth and/or nose, the adenoids can become inflamed as they try to fight off infection. This inflammation, and any infection that results despite the immune system's attempt to it fight off, can lead to enlarged adenoids.
In cases where enlarged adenoids are present without infection, it is often believed that there may be a genetic predisposition to large or problematic adenoids. Some people may be born with a tendency to have larger than normal adenoids, or the adenoids may swell in response to infection. If symptoms are severe and last a long time, surgery may be recommended to remove them.
Enlarged adenoids can cause a variety of symptoms, such as snoring, stuffy or runny nose, trouble breathing through the nose and trouble sleeping — or they may cause no symptoms at all. When symptoms become bothersome enough to see a health-care provider, he or she will usually check the adenoids to see if they are infected.
If the infection is caused by bacteria, the health care provider may prescribe antibiotics to help kill the bacteria and reduce inflammation in the adenoid tissue. Untreated, enlarged adenoids caused by infection can lead to secondary problems, such as ear or sinus infections. In cases where swollen adenoids are causing no symptoms, and may only be noticed, for example, upon a health-care provider’s examination, a wait-and-see approach to treatment may be recommended.
When enlarged adenoids cause symptoms that are severe and last a long time, surgery to remove them may be recommended. Called an adenoidectomy, this surgery is sometimes combined with tonsil removal, or tonsillectomy. The tonsils are located just below the adenoids and are made of a similar lymphatic tissue. They often become enlarged along with the adenoids in cases of infection.
If enlarged adenoids do not cause serious symptoms and/or any infections related to them can be effectively treated, many health-care providers often recommend leaving them in place. This is typically due to the fact that, in most cases, the adenoids get smaller and smaller as people get older. By the time a person reaches adulthood, the adenoids have usually shrunken to the point that they rarely cause problems.