What causes insomnia?


Insomnia and its causes

Being an extract from Chapter 4 of the following book:

Relax Your Way to a Better Life: Using Dr Jacobson’s progressive muscle relaxation technique for physical and mental health.

Hebden Bridge: The Institute for E-CENT Publications. Taylor-Byrne, R.E. (2020).


Here is the first half of Chapter 4:

Chapter 4:  How progressive muscle relaxation cures insomnia

”Habits of high nerve tension, in my opinion, are the cause of insomnia. To remove these you should learn to relax.”

Jacobson (2011).


What is insomnia?

Insomnia means the inability to get to sleep, or to stay asleep. People suffering from insomnia have the experience of taking a long time to get off to sleep at night, or they wake up in the night repeatedly, or very early in the morning.

And the mental anguish of being sleepless for long periods of time, when we want to sleep, can be very stressful. It is a truly unpleasant condition. Three different categories of insomnia have been identified:

– Transient: The inability to sleep lasts for less than one week. (Jet lag, noise, temporary problems, could all be causes).

– Acute: The problem lasts for less than one month. (The cause could be short term stress).

– Chronic: The inability to sleep persists for over one month. Indeed it could last for many years, especially if untreated.

Millions of people in the Western world have problems with insomnia.  Of those millions of people, only a small proportion have what could be called a ‘sleep disorder’.  The rest are struggling with a problem which can be fixed (sometimes easily; and sometimes with considerable difficulty), if they can discipline themselves to take remedial action.


The causes of insomnia

Not surprisingly, about 75% of cases of insomnia are triggered by some major stressor.”

(Sapolsky, 2004).[1]


What are the common causes of insomnia? There are many sources of insomnia: from lack of physical exercise; overuse of caffeine and recreational drugs and alcohol; to not understanding the negative effect that bright light – and especially blue light, from computers and mobile phones – has on the melatonin level in the body.

Blue light delays the release of melatonin. And melatonin is essential for the onset and maintenance of sleep: (it signals to the brain regions that generate sleep, that sleep must be started).  Other factors that can cause insomnia include:

– Having your bedroom too warm;

– taking medication for depression, asthma, birth control;

– having high blood pressure, heart disease, thyroid disease, nasal allergies;

– plus common cold remedies.

Certain medical conditions can bring about insomnia, and these range from: acid reflux at night, hyperthyroidism, lower back pain, Parkinson’s disease, asthma and chronic pain.

But one of the most frequent causes of insomnia, Walker (2017)[2] suggests, is that emotional preoccupations, (such as worry and nervousness), keep people awake at night; and these are due in part to the massive amounts of information people have to process every day.

This information overload includes their work commitments; email and mobile phone interruptions; interpersonal challenges; and pressure and concerns about the future. Jacobson concluded that many people, as they lie in bed, try to do two irreconcilable things: they want to get off to sleep, but they also want to find a solution to their problems.

Stress and insomnia

The effect of all this information overload, and other daily stressors, is that it creates worry and mental turbulence; and this results in increasing levels of tension in the body, which reacts by turning on the ‘fight or flight’ response of the autonomic nervous system.

Three things happen as a result:

– 1. The metabolic rate – (the speed at which energy is produced by the body when it’s at rest) – increases;

– 2. The body’s temperature goes up, which makes it difficult to sleep. (We need to lower our temperatures by a few degrees before we can sleep). And thirdly:

– 3. The raised levels of cortisol and adrenaline and noradrenaline, which are released into the body by the stress response, make a person more vigilant and alert, raising the heart rate. (This is the opposite of what we need for sleep. Under normal circumstances, when going from lighter sleep to deeper sleep, our heart rate slows down).

But because of these bodily changes taking place, the individual trying to get to sleep is overstimulated, which makes sleep much more difficult or even impossible to achieve.

During the day, it’s different: if our stress response is switched on by a challenging event, like being verbally attacked, or driving in very bad weather, then as soon as the event has taken place, we can move around physically, and thereby burn off the stress hormones through natural, daily, physical activity.

This cannot take place when we are lying in bed, and the body is over-aroused due to stressful memories, or information overload.

Research on insomnia

Here is a study which investigated people with chronic insomnia.  The research was done jointly by Penn State University; the Autonomous University of Madrid; and the University of Athens[3].

What the researchers found of significance was the way in which the insomnia sufferers handled their day to day stress. They tended to handle the stress and conflicts they experienced during the day by suppressing their emotions – keeping them inside themselves. This strategy led to emotional over-stimulation, as indicated by the fact that: “At bedtime they were characteristically tense, anxious and ruminative about issues associated with health, work, personal affairs, death, etc.”

Because those research participants were emotionally upset, their whole body became tense and agitated, and they had difficulty getting to sleep, or returning to sleep if they woke up in the night. The result was that they developed a dread of not being able to get to sleep, and this made them even more wound up, which kept them awake. And, in time, this became a vicious circle.

Brain scanning research has shown that people who fall sleep easily have different parts of their brains active, when they start to go off to sleep, than people who have insomnia (and cannot fall asleep easily). When members of the two different groups of people were (individually) placed in a brain scanner, there were real differences in their brain patterns of activity, as follows:

End of extract.



[1] Sapolsky, R.M. (2004) Why Zebras Don’t get Ulcers. Third Edition. New York: St Martin’s Griffin.

[2] Walker, M. (2017) Why We Sleep. London: Allen Lane.

[3] Basta, M., Chrousos, G., Vela-Bueno, A. and Vygontzas, A. (2007): ‘Chronic Insomnia and Stress system’. Sleep Medicine Clinics 2. Pages 279-91.  Cited in: Huffington, A. The Sleep Revolution: Transforming your life one night at a time. London: Penguin Random House, UK.