The upper airway of children may be compromised by large tonsils or adenoids. The back of the mouth and throat are proportionately smaller in children and have increased muscle tone compared to adults. The lymphoid tissue of the tonsils and adenoids grows in most children between the age of 2 and 6 years. In those who do not have room to spare, this growth may cause a narrowing that compromises the passage of air. This may lead to snoring or even sleep apnea in these children. The vast majority of children with large tonsils or adenoids never develop sleep apnea, however.
The degree of enlargement is assessed with a scale that attempts to objectively judge the size of the tissues and the risk for sleep-disordered breathing. This Brodsky scale grades the size of the palatine tonsils from 1+ to 4+. At the largest classification, the tonsils are touching in the midline of the throat. When these tissues reach a critical threshold, as determined by a doctor, there may be associated changes that lead to additional problems.
The disrupted airflow may lead to vibration (such as snoring) that causes swelling and redness within the tissues. There may also be recurrent infections. Other anatomic variations that may be associated with a narrowed airway, such as a short neck or small jaw, may also makes things worse.
If you are concerned about snoring or recurrent infection in your child, your doctor may evaluate the size of the tonsils. If these are determined to be enlarged, they may be removed with a surgery called tonsillectomy.
Durmer, JS et al. "Pediatric Sleep Medicine". Continuum. Neurol 2007; 13(3):153-200.