Adenoids: Definition, Anatomy, Associated Diseases, Causes, Symptoms, Diagnosis and Treatments

They are lymph nodes located in the back of the throat behind the nose.

Lymph nodes are part of the lymphatic system, which helps the immune system fight infection.

Other lymph nodes are found in many places, including the neck, armpits, chest, abdomen, and groin.

Together with the tonsils, they are part of the “first line of defense” that protects the body from infection .

Airborne germs that enter the body through the nose are filtered and trapped by hairs and mucus in the nose, and most are destroyed by antibodies and white blood cells produced by the adenoids.

In adults, both the tonsils and adenoids shrink. However, they can all become inflamed again with infections.

Adenoids trap germs when they enter the body. By doing so, they can sometimes temporarily swell while trying to fight an infection.

The swelling usually resolves on its own, but medical treatment is sometimes 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 at the same time.


The nasopharyngeal tonsil originates from the pharyngeal endoderm in the posterior midline of the nasopharynx .

Development begins during the late first trimester (third month) in association with the mucous glands of the pharynx and is fully formed by the seventh month of gestation.

The size of the amygdala increases during early childhood.

Adenoids begin to grow from birth and reach their maximum size when the child is between 3 and 5 years old.

After the age of 7, they shrink and generally begin to atrophy at the end of the first decade of life.

During adolescence, they are barely detectable and disappear completely when a person reaches adulthood.

Babies and very young children have undeveloped immune systems.

At that age, the adenoids are a useful support to fight infections.

Later in life, when the immune system is better developed and can deal with infections more effectively, they are not needed.


Adenoids are a pyramidal-shaped structure composed of lymphoid tissue.

The apex of this pyramid extends into the nasal septum, and the base is located on the posterior wall of the nasopharynx.

The adenoidal surface is inactivated by the number of folds with some crypts.

There is a pharyngeal bursa in the midline (Luschka’s bursa) that extends backward and upward.

This bursa represents the notochordal attachment site to the endoderm of the primitive pharynx.

Microscopically, the adenoids are covered by the same epithelium as the respiratory tract, that is, the pseudostratified ciliated columnar epithelium.

The epithelium covers the lateral organ and inferiorly with some small scattered patches of non-keratinized stratified squamous epithelium.

This epithelium also lines the series of folds of the mucosa.

Between the upper surface and the adjacent sphenoid and the occipital bone is a layer of connective tissue (hemicapsule) made up of reticular fibers.

This covering of connective tissue sends septa into the lymphoid parenchyma and subdivides it into 4 to 6 lobes.

Many sero-mucous glands are present within the connective tissue with their ducts extending through the lymphoid parenchyma.


The innervation of the adenoids is supplied by:

  • The glossopharyngeal nerve through the pharyngeal plexus.
  • The posterior palatal branch of the maxillary nerve.
  • Fibers of the lingual branch of the mandibular nerve.

Lymphatic drainage

Lymphatic drainage from the adenoid is performed into the pharyngomaxillary space and the retropharyngeal lymph nodes.

Arterial supply

The adenoids receive their blood supply from 6 arteries:

Ascending pharyngeal artery

This artery arises from the lower part of the external carotid artery.

It has anteriorly directed pharyngeal branches that supply the pharynx and associated structures.

Ascending palatine artery

This is a branch of the facial artery, and passes above between the stigoflossus and stylopharyngeal muscles.

In the upper part of its course, it passes between the superior constrictor of the pharynx and the internal pterygoid muscle.

Tonsillar branch of the facial artery

This branch emerges between the internal pterygoid muscle and the stiglogosus muscle.

The artery will also continue to enter the palatine tonsil and the posterior section of the tongue.

Pharyngeal branch of the maxillary artery

The maxillary artery is the seventh branch of the external carotid artery.

The pharyngeal branch is a branch of its third section.

Pterygoid canal artery

This is another branch of the third section of the maxillary artery and supplies the upper part of the pharynx and the auditory tube.

The basistophenoid artery

It is the branch of the inferior pituitary arteries, it supplies the bed of the adenoids.

Venous drainage

Venous drainage is through the internal and external submucosal venous plexus of the pharynx.

After emerging from the lateral surface of the tonsils, the draining veins join the paratonsilar veins that pierce the superior constrictor to join the pharyngeal venous plexus.

They can also drain into the internal jugular vein and facial veins.


Adenoid hypertrophy

In certain cases, adenoids can become infected in young children and not significantly atrophy.

Infections can also cause the adenoids to remain swollen and enlarged, even when the infection is no longer there.

This enlargement can affect nasal breathing, resulting in a nasal voice and mouth breathing.

They can also cause problems with sleep and cause apneic episodes or restlessness.

In this situation, the patient may require surgical removal of the adenoids to remove the obstruction.

Eustachian tube dysfunction

The Eustachian tube connects the middle ear to the nasopharynx.

Swollen and enlarged adenoids can block this duct and can cause middle ear infection, ie otitis media.

A blocked tube sucks the tympanic membrane inside creating negative pressure in the middle ear cavity leading to mild to moderate hearing loss.

Obstructive sleep apnea

This condition generally occurs in children during periods of sleep due to airway obstruction.

Palatine tonsils or adenoids can become enlarged to obstruct the airway.

There are episodes of blockage throughout the night, during sleep, resulting in a disrupted sleep pattern.

If the child has shown clear evidence of apnea episodes while asleep, then a tonsillectomy with concurrent adenoidectomy may be the best option.


Since the adenoids are constantly in the way of germs (microorganisms), infections are common.

Infected adenoids swell, which can reduce air flow through the nose.

Signs and symptoms of adenoid problems

Adenoid problems can cause the following signs and symptoms:

  • Snoring when asleep.
  • Speak with a “stuffy nose” sound.
  • The inability to pronounce certain consonants, including ‘m’ and ‘n’.
  • Dryness and sore throat due to mouth breathing (this is often a problem in the morning after sleeping with your mouth open).
  • Yellow or green snot from the nose.
  • Stuffy or stuffy nose.
  • Ear problems
  • Difficulty sleeping.
  • Throat pain.
  • Swallowing difficulties
  • The glands in the neck are swollen.

The main symptoms are caused by difficulty breathing through the nose.

Children with swollen or enlarged adenoids breathe loudly, usually through their mouths.

This makes the mouth dry and can lead to disturbed sleep at night.

In the condition called sleep apnea, a child stops breathing for a few seconds while asleep and then starts again.

Even after the infection clears, the adenoids can remain enlarged.

In some children, an allergic reaction can irritate the adenoids and cause them to swell. Some children can be born with enlarged adenoids.

If the adenoids become swollen, they can also block the Eustachian tubes, increasing the chances of a middle ear infection.

Some children have adenoids that are larger than normal, which can also affect their breathing.

There is also a link between large tonsils and adenoids and a condition called sticky ear.

This happens when the middle ear becomes blocked by a sticky substance that affects hearing.


Both bacteria and viruses can cause an infection.

These are generally taken as part of everyday life, so there is little you can do to prevent them, although good hygiene, including hand washing, is important.

Large adenoids can develop naturally in the uterus, doctors do not know what makes them grow larger than normal.


Adenoid infections can cause a variety of complications, including:

Middle ear infections

The adenoids are just at the end of the tubes from the middle ear to the throat (the Eustachian tubes).

Infections can spread to the ears from the adenoids and cause middle ear infections, which can affect hearing.

Glue on ear

The swollen adenoids block the Eustachian tubes and prevent the normal mucosa, which forms every day in the middle ear, from draining.

A build-up of sticky mucus interferes with the movements of the small bones in the middle ear, affecting hearing.


Air-filled cavities of the skull can also become infected.

Chest infections

Bacteria or viruses can infect other sites, such as the bronchial tubes (bronchitis) or the lungs ( pneumonia ).


The child may swallow a large amount of pus, usually at night while sleeping, which can lead to vomiting in the morning.

Diagnosis of adenoid problems

Ear problems can be a sign of swollen adenoids.

If a child suffers from constant upper respiratory infections, breathing difficulties, and ear problems, the doctor can diagnose a problem with the adenoids.

To do this, the doctor will check for inflammation by looking inside the throat with a small mirror and take a medical history.

A throat culture or strep test can help determine what infection, if any, is involved.

Blood tests can diagnose certain infections, such as mononucleosis.

A sleep study can determine if sleep problems are due to large tonsils and adenoids.

If your adenoids are part of an ongoing problem, your doctor may suggest surgery to remove them, called an adenoidectomy.

Treatment for infected adenoids

What is done to treat infected adenoids depends on the effects the adenoids are causing on the patient.

Thus, if the child has a middle ear infection or sinusitis, and the adenoids are swollen, treatment will aim to reduce the pain in the ears. And in case of infection antibiotics will often be used.

These treatments improve the health of the ears and sinuses, generally they will also help clear the infection in the adenoids.

It is rare that “infected adenoids” are the main reason for treatment.

Your doctor may recommend that you have your adenoids removed (adenoidectomy) if:

  • They have recurring ear infections, which are interfering with language development.
  • You often have a sore throat.
  • You have large adenoids that interfere with breathing, especially at night.


An adenoidectomy refers to the surgical removal of the adenoids. This is a quick and easy procedure with very few risks.

An adenoidectomy does not increase the risk of subsequent infections for the child. The immune system is able to deal with viruses and bacteria without the presence of adenoids.

Most doctors will not perform an adenoidectomy in very young children. The operation is usually carried out when the child is between 1 and 7 years old.

In rare cases, adenoids can grow back after being removed, but research suggests regrowth is not enough to cause nasal obstruction.

Adenoidectomy generally does not involve serious complications, especially if it does not accompany removal of the tonsils.


Adenoids are removed when they block breathing through the nose or cause chronic ear pain or deafness.

In childhood, the adenoids and tonsils are believed to play a role in fighting infection by producing antibodies that attack bacteria that enter the body through the mouth and nose.

In adulthood, however, the adenoids are unlikely to be involved in the body’s defense, as they normally shrink and disappear.

Between the ages of two and six, adenoids can become chronically infected, swollen, and cause problems in the body.

This can cause breathing difficulties, especially during sleep.

The swelling can also block the Eustachian tubes that connect the back of the throat to the ears, leading to hearing problems until the blockage is relieved.

The goal of an adenoidectomy is therefore to remove the infected adenoids.

Since they are often associated with infected tonsils, they are often removed as part of a combined operation that also removes the tonsils.


An adenoidectomy is done under general anesthesia.

The surgeon removes the adenoids behind the roof of the mouth.

This procedure can be done through the mouth or through the nose.

Excision through the mouth

Adenoids are usually removed through the mouth after an instrument is placed to open the mouth and retract the palate.

Various instruments can be used to remove the adenoids.

The patient’s mouth is held open with tubes. A mirror is used to view the adenoids behind the nasal cavity during the procedure.

Adenoids are removed in a side-to-side or front-to-back motion.

The bleeding is controlled with a cautery tool.

Excision through the nose

Adenoids can also be removed through the nasal cavity with a suction surgical instrument called a microdebrider.

With this procedure, bleeding is controlled with a suction packing or cautery.

Among the procedures to perform adenoidectomy we have:

Curette removal

The most common method of removal is to use the curette, an instrument that has a sharp edge perpendicular to its long handle.

A downward sweep is done in order to remove all the tissue, taking special care to avoid damage to the pharyngeal muscles.


Adenoids can also be removed by electrocautery with a laparoscopic electrode with irrigation and suction system, with a metal rim to achieve coagulation.

To be

The laser has also been used to remove adenoids. However, this technique is generally avoided as it has caused excessive scarring of the nasopharyngeal tissue.