Sleep is the only thing we do where effort defeats itself - the more you try to sleep the less you can. Sleep is the art of letting go.
About two thirds of the population experience occasional difficulties with sleeping and one third experience regular or chronic sleep problem. Insomnia is one of the most common conditions that people visit their doctors for.
Children do most of their growing during their sleep. Lack of sleep can therefore affect their growth.
One of the dangers of lack of sleep is unanticipated sleepiness.
In the UK, twice as many fatal accidents are caused by drivers falling asleep at the wheel than being under the influence of alcohol or drugs.
New studies are showing that lack of sleep can be a key cause of obesity.
People who get their full quota of sleep are healthier and live longer than those who try and get by on less.
Lack of sleep causes our immune system to become weakened.
People who claim to get by on just a few hours of sleep a night invariably sleep in on weekends to catch up - the new term for this is a "sleep camel".
The overwhelming view among scientists is that although we can survive on fewer, we need eight hours to function properly.
A New Scientist report said that sleep is not only important for physical rest, it plays a vital role in maintaining our intelligence. It’s claimed that we lose one point of our IQ for every hour of sleep lost.
A commission on sleep disorders reported in 1998 that Americans were sleeping 20% less than their great-grand-parents and the National Sleep Foundation in Washington says two out of five workers complain that fatigue interferes with their ability to function.
Large amounts of alcohol affect sleep patterns. Someone who’s drunk enough to make the room spin when they go to bed and then sleeps for 8 hours, will only get the equivalent of 2 hours of normal sleep.
Sleeping pills are often prescribed by doctors for convenience or lack of other options. They are recommended be given to people who are so stressed or traumatised that they can't sleep - and the course of medication should be for a maximum of two weeks. But in so many cases a dependency develops, turning into habitual use. These drugs interfere with normal sleep and the mental and physical processes which take place during normal sleep. They also cause a hangover in the morning which leaves people with reduced mental sharpness and vulnerable to accidents.
Research is now showing that lack of sleep causes sugar cravings.