The most common sleep disorder among those who seek help is obstructive sleep apnoea, when the airway becomes blocked during sleep and causes frequent pauses in breathing. In children, the airway tends to be blocked by enlarged adenoids and tonsils – tissue masses that fight infections. Tonsils are at the back of the throat and adenoids behind the nose and roof of the mouth.


Symptoms include snoring and gasping during sleep and excessive sleepiness in the day. About 1 to 3 per cent of children here have the disorder, often between the ages of two and six. This number is rising in tandem with that of children who survive prematurity, are obese and have allergic conditions – risk factors for the disorder, said Dr Tang.


Lifestyle changes have contributed to the increase.In 2007, 3.6 per cent of children here were obese, up from 2.8 per cent in 1994. This is probably because children exercise less and eat more fat and refined sugars. More are also being treated now due to greater awareness among doctors and parents of the disorder and its complications, Dr Teoh said. These include hypertension, delayed development, and death. In a 2002 study by Dr Tang on about 180 obese children with sleep apnoea, their intelligence quotient (IQ) grew by an average of five to six points one year after the sleep disorder was treated. It can be treated with surgery to remove the tonsils and adenoids, or by wearing an oxygen mask to sleep.