Sleep makes waking time more productive, yet a huge number of us suffer from sleep disorders, particularly insomnia.
The inability to sleep is unpleasant, affects our capacity to work, and prevents our being able to enjoy life to the full. Sleep deprivation can kill, through increased likelihood of accidents and altered metabolism that contributes to disease.
Why do we need sleep?
We have all experienced that free falling sensation when going to sleep, and the twitching and murmuring as we drift into what feels like oblivion, our unconscious state. But why do we need to go through this rather strange ritual of sleep?
Exactly how it produces benefits remains largely unknown but it is essential, with an average one third of our life-time being spent in a sleeping state.
The consensus of opinion is that it is necessary for rest, recovery, and recouperation. Yet there is still a great deal of brain activity during sleep; nerve cells fire up to 5 to 10 times more frequently during certain sleep stages than during hours of wakefulness.
One possible function is as a biological filing system for the previous days events, sorting out what has happened; the brain going 'off-line' to carry out jobs it cannot easily keep up with during waking hours.
Recent research suggests sleep strengthens memory - not so much remembering peoples' names but consolidating learning skills, improving the ability to perform tasks that were attempted whilst awake.
Insomnia - defining the sleep disorder
Insomnia is dissatisfaction with the amount or quality of sleep we are receiving: finding it difficult to get to sleep, staying asleep, or waking too early.
Individuals typically require eight hours a night, but some can live efficiently and to the full on only 4 hours, whilst others require up to 12 hours.
The pattern changes with age, older people often benefiting from a catnap in the middle of the day and needing less at night.
Suffering from insomnia does not mean you have inadequate sleep. You may actually be receiving plenty, but you don't feel as though you are, which causes worry and further sleep loss, establishing a vicious circle.
Other forms of sleep disorder
Other forms of sleep disorder include obstructive sleep apnoea and narcolepsy.
Obstructive sleep apnoea peaks at the age of 50. Breathing actually stops during sleep for ten seconds or more, due to an obstruction to airflow in the throat. The condition leads to repeated awakings during the night, often unrealised, to allow airways to reopen, with accompanied snoring. Although sleep apnoea and snoring are closely linked, snoring does not necessarily mean you have obstructive sleep apnoea.
Narcolepsy is a specific disorder in which there is an uncontrollable desire for sleep. An individual may suddenly change from a fully awake state to dreaming sleep, whilst engaging in normal daytime activities.
The scale of insomnia
- Insomnia affects nearly a third of the British population.
- 5 million people in Britain have impaired quality of life at some time in their lives due to chronic insomnia.
- One person in 11 suffers from the condition regularly for longer than 6 months at a time.
As the definition of normal sleep is not well established, estimates of the prevalence and severity of insomnia vary widely.
Approximately 13 million prescriptions for sleeping pills are issued in the UK each year. Since most cause drowsiness, they can impair the ability to think and drive a car the following day; they may lead to social dependency and cannot in any case give good quality deep sleep. It is important to find alternative means to deal with insomnia.
Written by K Mellish.