| How Much Sleep
do we Need?
The amount of sleep each person needs depends on many
factors, including age. Infants generally require about
16 hours a day, while teenagers need about 9 hours on
average. For most adults, 7 to 8 hours a night appears
to be the best amount of sleep, although some people
may need as few as 5 hours or as many as 10 hours of
sleep each day. Women in the first 3 months of pregnancy
often need several more hours of sleep than usual.
The amount of sleep a person needs also increases
if he or she has been deprived of sleep in previous
days. Getting too little sleep creates a "sleep
debt," which is much like being overdrawn at a
bank. Eventually, your body will demand that the debt
be repaid. We don't seem to adapt to getting less sleep
than we need, while we may get used to a sleep-depriving
schedule, our judgment, reaction time, and other functions
are still impaired.
People tend to sleep more lightly and for shorter
time spans as they get older, although they generally
need the same amount of sleep as they needed in early
adulthood. About half of all people over 65 have frequent
sleeping problems, such as insomnia, and deep sleep
stages in many elderly people often become very short
or stop completely. This change may be a normal part
of aging, or it may result from medical problems that
are common in elderly people and from the medications
and other treatments for those problems.
Experts say that if you feel drowsy during the day,
even during boring activities, you haven't had enough
sleep. If you routinely fall asleep within 5 minutes
of lying down, you probably have severe sleep deprivation,
possibly even a sleep disorder. Micro sleeps, or very
brief episodes of sleep in an otherwise awake person,
are another mark of sleep deprivation. In many cases,
people are not aware that they are experiencing micro
sleeps. The widespread practice of "burning the
candle at both ends" in western industrialized
societies has created so much sleep deprivation that
what is really abnormal sleepiness is now almost the
norm.
Many studies make it clear that sleep deprivation
is dangerous. Sleep-deprived people who are tested by
using a driving simulator or by performing a hand-eye
coordination task perform as badly as or worse than
those who are intoxicated. Sleep deprivation also magnifies
alcohol's effects on the body, so a fatigued person
who drinks will become much more impaired than someone
who is well rested.
Driver fatigue is responsible for an estimated 100,000
motor vehicle accidents and 1500 deaths each year, according
to the National Highway Traffic Safety Administration.
Since drowsiness is the brain's last step before falling
asleep, driving while drowsy can-and often does-lead
to disaster. Caffeine and other stimulants cannot overcome
the effects of severe sleep deprivation. The National
Sleep Foundation says that if you have trouble keeping
your eyes focused, if you can't stop yawning, or if
you can't remember driving the last few miles, you are
probably too drowsy to drive safely.
About the Author
Chris Read, An associated editor to Hateweight.com.
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