Adenoids are small lumps of tissue located at the back of the throat, above the tonsils. Together with the tonsils, they form the first line of defense in infants and young children, because they sample bacteria and viruses as they enter the body.
In this way, the adenoids are one of the many ways the body protects itself from harm and fights off infection.
Adenoids are also known as also known as the pharyngeal tonsil, or nasopharyngeal tonsil.
Adenoids start growing from birth, and they reach their peak size when the child is around 3 to 5 years of age. After the age of 7 years, they shrink. During adolescence, they are barely detectable and they disappear completely by the time a person becomes an adult.
Babies and very young children have undeveloped immune systems. At that age, the adenoids are a useful back-up for fighting off infections. Later in life, when the immune system is better developed and can cope with infections more effectively, they are not needed.
Unlike the tonsils, which can be seen if you open your mouth and look into the mirror, adenoids can only be seen when the doctor uses a light and a small mirror, or a flexible telescope.
Adenoids trap germs when they enter the body. In doing so, they can sometimes puff up temporarily as they try to fight off an infection. The swelling normally resolves on its own, but sometimes medical treatment is necessary.
If the bacterial invasion is very aggressive, the adenoids themselves can become infected.
Swollen or enlarged adenoids are common in children. Often, the tonsils will swell up at the same time.
Swollen adenoids may cause the following signs and symptoms:
- Blocked or stuffy nose, so that the child may breathe just through the mouth
- Ear problems
- Sleeping difficulties
- Sore throat
- Swallowing difficulties
- The glands in the neck seem swollen.
Even after the infection has gone, the adenoids may remain enlarged. In some children, an allergic reaction can irritate the adenoids, making them swell up. Some children may be born with enlarged adenoids.
If the adenoids swell, they may also block the Eustachian tubes, and this increases the chance of a middle ear infection.
If a child suffers from constant upper respiratory tract infections, breathing difficulties, and ear problems, the doctor may diagnose a problem with the adenoids.
To do this, the physician will check for inflammation by looking into the throat with a small mirror, and take a medical history.
A throat culture or strep test can help to determine which infection, if any, is involved.
Blood tests can diagnose certain infections, such as mononucleosis.
A sleep study can determine whether sleep problems are due to large tonsils and adenoids.
If the adenoids are part of an ongoing problem, the physician may suggest surgery to remove them, called an adenoidectomy.
An adenoidectomy refers to the surgical removal of the adenoids. This is a quick and straightforward procedure with very few risks.
An adenoidectomy is not thought to increase the risk of subsequent infections for the child. The immune system will be able to cope with viruses and bacteria without the adenoids.
Most doctors will not perform an adenoidectomy on very young children. The operation is normally carried out when the child is aged from 1 to 7 years.
Sometimes, the doctor will surgically remove the tonsils at the same time. This is called a tonsillectomy.
In rare cases, the adenoids may regrow after being removed, but research suggests that the regrowth is not sufficient to cause nasal blockage.
Adenoidectomy does not generally entail any serious complications, especially if it does not accompany the removal of the tonsils. However, research has suggested that may not necessarily provide any more benefit than watchful waiting.
There is also evidence that upper respiratory tract infections recur after adenoidectomy, at a reported rate of 12 percent in the U.S. and 60 percent in the Netherlands.