Are you having difficulties sleeping?

If you fall asleep five minutes after hitting the pillow, then you could be suffering from sleep deprivation.

Often people mistake the ability to fall asleep easily as soon as they get into bed as healthy as opposed to spending hours ‘counting sheep’ in the dark.

People who suffer from sleep deprivation often experience "microsleeps", which are short bursts of sleep in an otherwise awake person.

Feeling tired or drowsy during the day is a symptom of not having enough sleep.

There are over 20 definitions of "sleep" in several dictionaries.

The first, a verb, seems most appropriate:

"To take the rest afforded by a suspension of voluntary bodily functions and the natural suspension, complete or partial, of consciousness; to cease being awake."

Physiologically, sleep is a complex process of restoration and renewal of the body.

Scientists still do not have an explanation as to why humans have a need for sleep.

Deprivation

Sleep is not merely switching off the body functions, but is believed to be important in many physiologic processes including the processing of experiences and the consolidation of memories.

Therefore, people suffering from sleep disorders do not get adequate or restorative sleep, and this is associated with a number of both physical and emotional disturbances.

Sleep is influenced by the regular body changes in mental and physical characteristics that occur in the course of about 24 hours.

These are controlled by brain neurons that respond to light, temperature, hormones and other signals and comprise the body’s biological clock.

This clock helps regulate the normal awake and sleep cycles.

Disruption of these cycles can make people sleepy when they want to be awake.

Consequently, this affects their ability to concentrate at work and as a result, interferes with their performance.

As people age, their sleeping cycle also changes. Older people are also more easily aroused from sleep.

Some people believe that older people need less sleep.

There is no scientific evidence that older people need less sleep than younger ones.

The amount of sleep one needs varies from one individual to the next.

There are no established criteria to determine exactly how much sleep a person needs but usually, eight hours or more may be necessary for some while others may consider this too much sleep.

On average, most adults need about seven to nine hours of sleep each night. On the other hand, newborns sleep from 16 to 18 hours a day.

There is evidence that some aspects of sleep are under genetic influence.

Researchers are currently investigating a gene believed to cause people that possess it to require only about six hours of sleep.

Researchers have only begun to examine the genetics involved in sleep.

Sleep

Suffering from a sleep disorder is a mind boggling thing. Usually people try different home remedies to induce sleep.

Therefore, it is critical to practise a good sleeping routine, like maintenance of a regular bedtime and awakening schedule.

This is the best way to ensure a restful and restorative sleep.

In order to sleep soundly, you must avoid habits that can interrupt your sleeping pattern.

This means you should avoid alcohol, nicotine and strenuous exercise in the hours prior to bedtime to help improve the quality of your sleep.

While more research is needed to explore the links between chronic sleep loss and health, it’s safe to say that sleep is too important to shortchange.

So when you wake up in the morning, do you feel refreshed and ready to go or groggy and grumpy? For many people, the latter is all too common.

Next week, we take a look at sleep disorders.

The author is the head of planning, monitoring and evaluation at Kenya Medical Research Institute (KEMRI)