Until recently, physicians seldom suspected that the course of an illness might be altered by sleep or that some illnesses might manifest themselves only in sleep. A connection to sleep, however, has proven to be the thread binding together a multiplicity of disorders.

• Sleep consumes about 25 years of our lives
• An estimated one person out of ten has some degree of disturbed breathing in sleep.
• One out of five American workers rotate shifts, constantly disrupting their sleep/wake cycle.
• One out of five Americans report that the quality and amount of their sleep is frequently or constantly unsatisfactory.
• Many people complain about excessive daytime sleepiness and in some, this may lead to traffic- or work related injuries.