Adenoids Dr Trisha Macnair The adenoids normally play an important part in the body's immune defence against invading micro-organisms, but sometimes they can cause problems.

In this article

What are they? Why causes enlargement?

Who's affected? What are the symptoms?

What's the treatment?

The adenoids are lumps of lymphatic tissue (sometimes called lymph glands or lymph nodes) at the back of the nasal passages. They're rather like tonsils but found higher up above the throat.

A child may be born with large adenoids, which have developed in the womb.

More commonly, the adenoids become enlarged during the first few years of childhood. Repeated infections of the upper respiratory system cause the adenoids to become chronically inflamed and enlarged. The tonsils are also usually enlarged.

Enlarged adenoids are common during childhood but in most cases are mild or only temporarily enlarged.

Enlarged adenoids tend to get better as a child reaches adolescence but occasionally problems persist into adulthood.

Enlarged adenoids may block the breathing passages, making a child breathe through the mouth. Mouth breathing may at first only be a problem at night, but in severe cases the child may breathe through their mouth during the day, too. Mouth breathing causes a dry mouth and cracked lips.

There is often bad breath, caused by chronic infection in the adenoids and aggravated by the dry mouth. Enlarged adenoids may also alter the sound of speech.

Other problems include ear infections (because the drainage tubes from the middle ear may be blocked), snoring and sleep apnoea. Disruption of sleep can interfere with a child's growth. In extreme cases, enlarged adenoids can put excessive strain on the heart.

It may be possible to see when tonsils are enlarged, but adenoids can only be seen using a special mirror or by putting a small flexible telescope called an endoscope into the nasal passages. This must be done by an ear, nose and throat specialist. Occasionally, x-rays or special sleep studies are necessary.

Antibiotics may be used to treat the adenoids when they're infected but may not have much effect on chronically enlarged adenoids.

An operation to remove the adenoids, called adenoidectomy, may be necessary in severe cases to prevent the long-term complications of airways obstruction, such as heart failure. Surgery may lead to improved growth and development because deep sleep is restored.

This article was last medically reviewed by Dr Rob Hicks in October 2007