Insomnia is a disorder in which it is hard to fall or stay asleep. It has repercussions for work, family and social life.

Insomnia overview

Insomnia is a common disorder in which a person has difficulty falling asleep, staying asleep, or suffers from non-refreshing sleep. This, in turn, affects the person’s ability to function during the day. Disrupted sleep affects a person’s mood, which may have an effect on family life and relationships. It also affects concentration, increasing the risk of poor productivity at work/school and of vehicle or occupational accidents.

Many factors can cause insomnia. Stress, anxiety and depression are common causes. Caffeine, alcohol, and many prescription drugs can also interfere with sleep. Insomnia may even result from a person convincing themselves that they will not be able to sleep – so-called ‘learned’ insomnia. In certain cases, however, there will be no obvious cause, and this is known as ‘primary’ insomnia.


Insomnia symptoms include difficulty falling asleep at night, waking during the night, awakening too early in the morning, or not feeling well-rested after a night’s sleep. A person with insomnia will often take 30 minutes or more to fall asleep, and they may frequently get less than six hours of sleep a night.

Consequently, insomnia is associated with reduced alertness, irritability, depression, and sleepiness during the day. A person with insomnia will have difficulty paying attention or focusing on tasks, and will make more frequent errors.

Insomnia can also be a symptom itself; for example, it can be caused by another physical or mental disorder such as depression.


Insomnia is the most common sleep disorder, chronically affecting approximately 10–15% of the population. The risk of insomnia increases with age; a US study revealed that 29% of adults aged over 65 years have some difficulty in falling asleep or staying asleep.

The prevalence of sleeping problems varies with geographic location – 56% of people in the US, 31% in Western Europe, and 23% in Japan, have reported difficulty with sleeping.

Insomnia constitutes a large cost to society, which a Canadian study estimated at approximately $5,000 per person every year. Most of this cost was due to reduced productivity at work (76%) and absenteeism (15%).

Very few people suffering from insomnia go to see a doctor, making it an under-diagnosed and under-treated disorder. In a European survey, it was found that 37% of people with insomnia took no action to resolve it at all, 10% used over-the-counter remedies, and 13% adopted non-pharmacological measures.

Seeking diagnosis and care

Diagnosis of insomnia by a doctor consists of an account of the patient’s history, a physical examination, and blood tests. The patient may be asked to complete a ‘sleep diary’ over a period of a week or more.

Insomnia can be treated with a combination of sleep hygiene, cognitive behavioural therapy, and medication. Sleep hygiene covers topics such as establishing a sleep routine, exercising frequently, and avoiding lying awake in bed. Various behavioural therapies can also be used, such as relaxation, postponing bedtime, and sleep restriction.

If the sleep disorder is chronic and unresponsive to treatment, then referral to a sleep specialist or assessment in a sleep laboratory may be required.

It is essential to receive professional advice before seeking treatment.



1. Insomnia. January 2011. Accessed 08/09/11.

2. Kandel ER, Schwartz JH, Jessell TM. Principles of neural science. © The McGraw-Hill Companies Inc: 2000.

3. Zammit GK, Weiner J, Damato N, et al. Quality of life in people with insomnia. Sleep 1999; 22 (Suppl 2): S379–S385.

4. Szuba MP, Kloss JD, Dinges DF (Eds). Insomnia. Principles and management. © Cambridge University Press, 2003.

5. American Psychiatric Association (APA). Diagnostic and Statistical Manual of Mental Disorders. Fourth Edition. Text Revision. DSM-IV-TR™. © 2000 American Psychiatric Association.

6. Foley DJ, Monjan AA, Brown SL, et al. Sleep complaints among elderly persons: an epidemiologic study of three communities. Sleep 1995; 18 (6): 425–432.

7. Léger D, Poursain B, Neubauer D, Uchiyama M. An international survey of sleeping problems in the general population. Curr Med Res Opin 2008; 24 (1): 307–317.

8. Daley M, Morin CM, LeBlanc M, et al. The economic burden of insomnia: direct and indirect costs for individuals with insomnia syndrome, insomnia symptoms, and good sleepers. Sleep 2009; 32 (1): 55–64.

9. Estivill E. Behaviour of insomniacs and implication for their management. Sleep Med Rev 2002; 6 (Suppl 1): S3–S6.