The Sleep Apnea Syndrome

A sleep apnea is defined as a lack of detectable nasal or oral breathing for at least 10 seconds. A hypopnea is defined as a reduction of normal nasal breathing up to 50% or less accompanied by sleep arousal. Apnea and hypopnea are not, however, differentiated in clinical routine. The severity of an apnea is therefore measured using the Apnea-Hypopnea-Index (AHI).

The AHI distinguishes between three levels of severity: a mild sleep apnea is up to 15 breathing reductions/pauses per hour, a moderate apnea is 16-30 breathing reductions/pauses per hour and a severe sleep apnea is more than 30 breathing reductions/pauses per hour.

With a mild sleep apnea, a patient is likely to fall asleep during passive periods (ex. watching television). With a moderate sleep apnea, a patient is likely to fall asleep during activities with a low level of concentration (ex. concerts or meetings).
With a severe sleep apnea, a patient is likely to fall asleep during highly concentrated activities (ex. while driving, eating or even speaking).

Severe forms of apnea require sleep laboratory testing and observations. In such cases, a CPAP-therapy  (continuous positive airway pressure) is often prescribed. Slight forms are most often successfully treated with intraoral therapy .