Sleep apnea often goes undiagnosed

Six months ago, 11-year-old Henry Leung began to exhibit some strange sleeping behaviour. He would suddenly sit upright, and his mother would have to wake him up and tell him to lie down again. Leung was unable to get any quality sleep. As a result, the Primary Six student often dozed off in class the next day, and was scolded by teachers.

At first his mother didn't think it was too serious. But eventually, when his daytime sleepiness started to affect his learning at school, she took him to see a doctor.

Henry was diagnosed as having sleep apnea, a condition in which the subject's breathing stops abnormally during sleep. His doctor, paediatrician Daniel Ng Kwok-keung, says Henry's condition was particularly severe, with pauses in breathing of more than 100 times an hour, each lasting 10 seconds.

The initial lack of concern about Henry's disrupted sleep is a common reaction among sleep apnea sufferers, doctors say, which explains why the condition often goes undiagnosed.

Jamie Lam Chung-mei, president of the Hong Kong Society of Sleep Medicine and a specialist in respiratory medicine, says that diagnosis is commonly delayed by an average of seven years among children, and 3.3 years for adults.