Sedating antihistamines for insomnia
For example, travelers experience "jet lag" when they cross time zones.
Scientists still do not have a definitive explanation for why humans have a need for sleep.It may take several days to reset a person's biologic clock, depending on how much it has been altered by the time change.Different organ systems in the body recover at different rates.Sleep typically occurs in cycles that range from 90 to 120 minutes in length, with 4 to 5 cycles occurring during each night's sleep.In the first half of the night, there is a transition from wakefulness into stage N1 sleep, then to stages N2, and N3.Sleep disorders are disruptions of the sleep cycle or the quality of sleep.
About 50 to 70 million Americans are believed to suffer from chronic sleep disorders, with millions more affected on an occasional basis.
The importance of sleep is underscored by the symptoms experienced by those suffering from sleep problems.
People suffering from sleep disorders do not get adequate or restorative sleep, and sleep deprivation is associated with a number of both physical and emotional disturbances.
Older people are also more easily aroused from sleep.
While some people believe that older adults need less sleep as they get older, there is no scientific evidence that older people need less sleep than younger adults.
Typically, there is a greater portion of N sleep in the first half of the night and REM sleep in the later portion of the night.