The adenoids are made up of lymph nodes, which form part of the body’s defences against upper respiratory tract infections. They are a mass of glandular tissue at the back of the nasal passage above the tonsils. They tend to enlarge during early childhood, a time when such infections are frequent.
The adenoids shrink in most children after the age of five years and disappear altogether by puberty. However, in some children they enlarge, obstructing the passage from the nose to the throat and causing snoring, breathing, and a characteristically nasal voice. The Eustachian tubes, which connect the middle ear to the throat, can also become blocked, resulting in recurrent middle ear infection and deafness.
Obstruction to the flow of secretions behind the nose can result in rhinitis (inflammation of the nose), which may spread to the middle ear and to the air sinuses behind the nose (see sinusitis).
As the child grows infections usually become less frequent. If they do not adenoidectomy (surgical removal of the adenoids) may be recommended.