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Adenoid hypertrophy (or enlarged adenoids) is the unusual growth ("hypertrophy") of the adenoid tonsil first described by the Danish physician Wilhelm Meyer (1824-1895) in Copenhagen in 1868. He described that a long term adenoid hypertrophy will cause an obstruction of the nasal airways. These will lead to a dentofacial growth anomaly that was defined as "adenoid facies" (see long face syndrome). There is very little lymphoid tissue in the nasopharynx of young babies; humans are born without substantial adenoids. The mat of lymphoid tissue called adenoids starts to get sizable during the first year of life. Just how big the adenoids become is quite variable between individual children. ==Signs and Symptoms== Enlarged adenoids can become nearly the size of a ping pong ball and completely block airflow through the nasal passages. Even if enlarged adenoids are not substantial enough to physically block the back of the nose, they can obstruct airflow enough so that breathing through the nose requires an uncomfortable amount of work, and inhalation occurs instead through an open mouth. Adenoids can also obstruct the nasal airway enough to affect the voice without actually stopping nasal airflow altogether. Nasal blockage is determined by at least two factors: 1) the size of the adenoids, and 2) the size of the nasal pharynx passageway. The adenoid usually reaches its greatest size by about age 5 years or so, and then fades away ("atrophies") by late childhood - generally by the age of 7 years. The lymphoid tissue remains under the mucosa of the nasopharynx, and could be seen under a microscope if the area was biopsied, but the mass is so reduced in size that the roof of the nasopharynx becomes flat rather than mounded. Just as the size of the adenoids is variable between individuals, so is the age at which adenoids atrophy. The symptoms caused by enlarged adenoids are mostly due to ''where'' this lymphoid tissue is located. The adenoids are in the midline of the nasopharynx, and the Eustachian tubes open from either ear to the right and left of them. In children with excessive middle ear infections and chronic middle ear fluid, there is a high bacterial count in the adenoids as compared to children without problematic otitis media, even if the size of the adenoids is small. The adenoids in these cases provides a reservoir of pathogenic bacteria that cause ear infections and subsequent middle ear effusions (fluid). The nasopharynx lies right above the throat. Splashes of excessive "drip" from infected adenoids may land directly on the vocal cords. Although the larynx and vocal cords do not ordinarily become infected from adenoiditis, their mucosa does become irritated. The vocal cords are extremely sensitive to touch, and any fluid drops falling on them cause an irresistible urge to cough. Adenoiditis therefore is one of the causes of cough. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Adenoid hypertrophy」の詳細全文を読む スポンサード リンク
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