Narrowed breathing passages make breathing more difficult during sleep
When someone falls asleep, the muscles of the throat relax and the breathing passages at the back of the nose and in the throat become narrower. In children, the tonsils and adenoids can grow to be quite large, and less air gets through the breathing passages during sleep. When this happens, you may notice snoring or noisy breathing.
Snoring is more common during some phases of sleep
There are some times during sleep when the muscles are more relaxed. Snoring is more common during these phases of sleep. This is why snoring can be more common in the second half of the night.
Snoring needs checking
Snoring is not always a very serious problem for children – about 15 to 20 in 100 children snore. But, it is a symptom that needs checking by your healthcare provider as 2 to 5 in 100 children have OSA.
Reasons for OSA
In children, the most common reason for OSA is enlarged tonsils and adenoids. In older children and teens, being overweight is a common reason. Any medical condition that affects the size and shape of your child's breathing passages can also make OSA more likely.
The image below shows an open mouth with enlarged tonsils.
Image credit: Klem via Wikimedia Commons(external link)