Insomnia Explained

What is insomnia?

Insomnia, the word comes from the Latin “in” (no) and “somnus” (sleep), and was first described by Johann Heinroth in 1818 [3]. 

According to the Diagnostic and Statistical Manual of Mental Disorders, insomnia is a:

dissatisfaction with sleep quantity or quality that results in clinically significant distress or impairment in social, occupational, or other important areas of functioning [4]. 

Moreover, the International Classification of Sleep Disorders 2 classifies three types of insomnia, being:

  • Mild insomnia
  • Moderate insomnia
  • Severe insomnia

Each of the above forms of insomnia are classified based on how much of an impact a lack of sleep has on social and occupational activities [3]. 

If you suffer from moderate or severe insomnia then it is important to seek treatment as this form of insomnia can lead to serious impairments at work and at home.

Three Types of Insomnia

  • Transient insomnia (mild)

This is characterised by only brief periods of poor sleep, perhaps a night here and there.

  • Acute insomnia (moderate)

Acute insomnia is when a person has persistent sleeping problems that lasts for more than three weeks.

  • Chronic insomnia (severe)

Chronic insomnia lasts for extended periods of time.

People with more severe insomnia (acute or chronic) usually have difficulty falling asleep (sleep onset), staying asleep (sleep maintenance) and/or seem to wake up too early in the morning [5].

As a consequence, insomniacs are at a far greater risk of workplace injury or accidents.

Causes of Insomnia

But where does this sleep insufficiency come from? 

It’s not hard to answer.

In our modern, fast-paced society we lose sleep from such things as:

  • Work demands
  • social/family responsibilities
  • Medical conditions
  • Sleep disorders

This can lead us to a kind of ‘sleep debt’, which lowers our overall physical performance, increases our risk of accidents and affects us psychologically.


Global Insomnia Epidemic

According to the vast array of scientific literature:

a whoping 15% of the global population suffer from chronic insomnia [5].

The other worrying fact is that insomnia is largely under-recognized and under-treated [6].

This leads to a significant loss in overall quality of life for many people.

Ordinary people might not be fully aware that their lack of quality sleep is having a profound impact on the their daily life.

Just for some general statistics, one scientific review article suggested:

diagnosed insomnia in both the UK and North America is somewhere between 5-15%.

More startling is that possibly up to 40% of the population show symptoms of daytime tiredness or sleepiness [5].

Nonetheless, insomnia can impede upon our daily activities and tasks by rendering us less productive and with less energy.

Insomnia in the UK


A recent UK survey asked 500 people a simple question:
How often do you have trouble falling asleep?

Of those that responded:

  • 22% said that they do indeed have trouble falling asleep.
  • 27.5% of women have trouble falling asleep.
  • 18.5% of men have trouble falling asleep [7].

This is a clear indication that inadequate sleep is becoming a problem in the UK.

Without proper sleep, we can expect to have a harder time forming new memories and focusing on day to day tasks.
If we magnify the problem of inadequate sleep, we can find it has an anatomy and complexity of its own.
Often a link can be made to problems surrounding non-REM and REM sleep.