The adenoids, also called pharyngeal tonsils, are the main component of the pharyngeal lymphatic ring. The pharyngeal lymphatic ring is an important line of defense of the upper respiratory tract. Essentially, the adenoids are lymphatic tissue structures composed of a variety of immune cells, and are one of the organs of human immunity, which have a role in maintaining the normal immune function of the pharyngeal cavity and the whole body. However, its physiological function is often overlooked when people emphasize its harmful effects, and blind removal may cause a decrease in local immune function. The adenoids are located at the upper end of the upper respiratory tract (top of the nasopharynx) and are susceptible to attack by viruses and bacteria entering the respiratory tract. Clinically, adenoid lesions are mainly manifested as hyperplastic hypertrophy of the glands (of course, not all adenoid lesions have to be significantly enlarged, and from this perspective, it seems that it may be more appropriate to call them adenoiditis). It is very important that the diagnosis of adenoid hypertrophy is established by the presence of diseases or signs and symptoms that may be associated with it, in addition to the manifestations of adenoid hypertrophy. For example, adenoid hypertrophy may cause rhinitis sinusitis, otitis media, pharyngitis, recurrent upper respiratory tract infections, adenoidal facies, sleep snoring or even breath-holding, etc. So, how big are adenoids considered to be hypertrophy? There is no uniform standard for this. The common way to determine this is by taking a lateral nasopharyngeal film and measuring the A/N value, which simply means the ratio of the adenoids to the nasopharyngeal cavity. If the value is greater than 0.6 (some scholars believe it is greater than 0.7), the adenoids are considered to be hypertrophic. The greater the value, the more severe the hypertrophy of the adenoids. Another way to determine this is to look at the degree of adenoidal obstruction of the posterior nostril through endoscopy, the higher the degree of obstruction the higher the degree of adenoidal hypertrophy. The pathological damage caused by adenoid hypertrophy can be considered in two ways: First, the adenoid hypertrophy itself obstructs the surrounding natural cavities and causes lesions in the surrounding organs. For example, glandular compression or obstruction of the pharyngeal orifice of the eustachian tube can cause secretory otitis media; obstruction of the posterior nostril can cause nasal congestion and obstruction of airflow due to narrowing of the airway can cause snoring or sleep apnea syndrome (OSAHS). Secondly, adenoids as a focal point of infection affects the surrounding organs. Forward, it can cause rhinitis and sinusitis, and to the sides, pathogens in the adenoids can invade the eustachian tube and cause otitis media. Moreover, because the adenoids are at the upper end of the upper respiratory tract, purulent or germ-laden secretions downward can cause pharyngitis, tracheitis, and even recurrent bronchopneumonia. In addition, long-term swallowing of secretions into the digestive tract can also cause dyspepsia, which in turn can lead to nutritional dysplasia: including calcium deficiency, inattention, hyperactivity, irritability, and other neurotoxic manifestations. Since most adenoid hypertrophy is associated with bacterial infections, the long-term presence of drug-resistant pathogens in the glandular tissues and their role as foci of disease are even more important. Therefore, the treatment of adenoid hypertrophy disease does not only emphasize the harm caused by its hypertrophy, but also focuses more on the harm caused by its role as a foci of infection. The presence of inflammation in the surrounding organs can also affect each other and the adenoids, leading to a vicious cycle of lesions. For example, adenoid hypertrophy can cause recurrent or persistent attacks of tonsillitis and rhinosinusitis, which in turn can lead to the persistence or development of adenoid hypertrophy. The main factor causing adenoid hypertrophy is primarily a germ infection, but there are other factors as well. Of greater concern now is allergic reactions, which are allergenic stimuli that cause adenoid hyperplasia, including dust mites and pollen inhaled from the respiratory tract and eating certain foods. It is not known whether adenoid hypertrophy is related to gastroesophageal reflux. How is adenoid hypertrophy treated? One view (mostly by pediatricians) emphasizes that the adenoids themselves have some immune function and recommends medication, including topical nasal sprays, anti-inflammatory drugs, antibiotics, calcium supplements, and herbal treatments. Another viewpoint (mostly otolaryngologists) emphasizes the impact of adenoid hypertrophy on the child’s breathing and development, and recommends early surgical removal. Objectively speaking, due to the inherent traumatic and dangerous nature of surgery, it is still prudent whether to use it or not. The understanding of the indications for surgery is mainly the grasp of “degree”, and the concept of individualized treatment should be applied flexibly. In clinical practice, we often encounter children with obvious adenoid hypertrophy, rhinosinusitis, or even full sinusitis (possibly allergic rhinitis), but after treatment with medication, the sinusitis is cured within a short period of time and the adenoids shrink, so of course these children do not need surgery. However, there are some children who have been diagnosed with adenoid hypertrophy and have been treated with medication for a long time, even seeking medical help and using “prescriptions”, but their symptoms do not improve in half a year or even a year. As mentioned earlier, in children with allergic rhinitis, adenoid hypertrophy may be a manifestation of local inflammation, and surgical removal is not helpful in treating the primary disease, so it is recommended not to choose surgical treatment.