Sleep Cycle
It's natural to blame sleep problems on stress or physical changes that come with age. But many cases of either sleeplessness or poor sleep are caused by a handful of specific problems, most of them fixable with lifestyle changes or the help of a doctor. Here, five little-known causes of sleep problems and what to do about them.
1. Light
How it disrupts sleep: You probably already know that when you stay up late under bright lights, you interrupt your body's natural sleep-wake cycle, because light tricks your brain into remaining in daylight mode. Less well known is that the light from computer screens and iPads shining directly into your eyes at close range is especially troublesome. Why? Part of the problem is that the light from these devices is at the blue end of the spectrum, which scientists believe is particularly disruptive to circadian rhythms. Blue light, although common during the day, doesn't occur naturally during the evening.
Similarly, light shining in your eyes while you sleep -- even very small amounts coming from, say, a lighted clock -- makes your brain think it's morning and emerge out of deep sleep. Darkness triggers production of the hormone melatonin, the hormone that triggers sleepiness and the onset of sleep. Light prevents this release or shuts it off.
The evidence: Studies have long shown that shift workers and those who work late at night have poorer sleep and higher incidences of certain conditions associated with lack of sleep than those who regularly sleep eight or nine hours at night. A recent study published in Cancer Causes & Control, for example, found that the countries generating the most light at night have the highest incidence of breast cancer. And studies at the Light Research Center at Thomas Jefferson University in Philadelphia have found that the use of computers, lighted readers, and TVs at close range is tied to a higher incidence of sleeplessness.
Who's at risk: Everyone exposed to light shortly before bed or
1. Light
How it disrupts sleep: You probably already know that when you stay up late under bright lights, you interrupt your body's natural sleep-wake cycle, because light tricks your brain into remaining in daylight mode. Less well known is that the light from computer screens and iPads shining directly into your eyes at close range is especially troublesome. Why? Part of the problem is that the light from these devices is at the blue end of the spectrum, which scientists believe is particularly disruptive to circadian rhythms. Blue light, although common during the day, doesn't occur naturally during the evening.
Similarly, light shining in your eyes while you sleep -- even very small amounts coming from, say, a lighted clock -- makes your brain think it's morning and emerge out of deep sleep. Darkness triggers production of the hormone melatonin, the hormone that triggers sleepiness and the onset of sleep. Light prevents this release or shuts it off.
The evidence: Studies have long shown that shift workers and those who work late at night have poorer sleep and higher incidences of certain conditions associated with lack of sleep than those who regularly sleep eight or nine hours at night. A recent study published in Cancer Causes & Control, for example, found that the countries generating the most light at night have the highest incidence of breast cancer. And studies at the Light Research Center at Thomas Jefferson University in Philadelphia have found that the use of computers, lighted readers, and TVs at close range is tied to a higher incidence of sleeplessness.
Who's at risk: Everyone exposed to light shortly before bed or