Adenoids are masses of lymph tissue, located behind the roof of the mouth and nose, in the pharynx. They are not visible. Similar to tonsils, adenoids help you fight infection as the first line of defence against bacteria and viruses. Adenoiditis is the inflammation of these glands. Adenoiditis mainly occurs in children below 15 years of age, and incidence decreases with age. The condition is rare after 15 years of age although not unheard of. Adenoiditis is a very common disease, with approximately10 million cases reported each year. It is a communicable disease and spreads through airborne respiratory droplets and saliva.