Sleep and Health

Abstract

There are epidemiological data to suggest that an optimal amount of sleep is associated with longevity. That is, too much or too little sleep does not promote good health. Sleep deprivation studies have shown the extreme sensitivity of humans to modest sleep deprivation, and have documented the enormous recuperative powers of sleep. Sleep can be objectively studied by recording brain wave activity and other physiologic measures which allow the determination of specific stages of sleep generally described as rapid eye movement (REM) sleep and non-REM sleep. These states of consciousness oscillate with a regular periodicity throughout the night, and thematic dreaming is generally associated with REM sleep. REM sleep also is associated with marked alterations in physiologic functioning which may create risk of for respiratory and cardiovascular disturbance. Sleep is largely controlled by the circadian temperature cycle which regulates the onset of REM sleep and the total duration of sleep. Clinical sleep disorders are common and have significant behavioral and physiological consequences. The most prominent of these would be obstructive sleep apnea and insomnia. Obstructive sleep apnea is caused by upper airway occlusion during sleep and is associated with significant cardiopulmonary consequences, sleep fragmentation, and excessive daytime sleepiness. Insomnia is perhaps the most common clinical complaint concerning sleep and is commonly associated with significant behavioral abnormalities such as anxiety, depression, and the conditioning of poor sleep habits.