Southern Cross Medical Library

Southern Cross Medical Library

Insomnia is a sleeping disorder characterised by poor quality or quantity of sleep. Reduced ability to perform daytime activities is the defining symptom of insomnia. Treatment involves medical and non-medical therapies.

People with insomnia find it difficult to fall asleep and/or stay asleep despite adequate opportunity and time to sleep. Insomnia is very common. It affects people of all ages, including children, but is more common in adults and the elderly. In a recent study of sleep habits among New Zealanders, 45% of participants reported experiencing insomnia symptoms at least once per week.


Many people experience temporary (or acute) insomnia, lasting for a few days or weeks, at some point in their lives. Some people, however, develop persistent (or chronic) insomnia, which lasts for a month or more.

Temporary insomnia

Many cases of insomnia are due to temporary issues or stresses, including the following:

  • Jet lag
  • Physical discomfort
  • Working different shifts (working a late or early shift can disrupt your circadian rhythm - the body’s internal clock)
  • Stressful life situations, such as divorce, death of someone close, losing a job, concerns about work, school, health or family
  • Caring for babies with colic or other health issues
  • Recreational drug use
  • Cigarette smoking
  • Caffeine intake prior to going to bed
  • Alcohol intoxication or withdrawal
  • Eating too much food late in the evening
  • Certain types of medication.

Persistent insomnia

Persistent insomnia is most often caused by underlying chronic medical or psychiatric conditions and poor sleep habits. Poor sleep habits include an irregular sleep schedule, using the bedroom for non-sleep activities, eating or exercising immediately prior to sleep, sleeping in a room with too much noise or lighting, or doing work in bed. The many medical conditions that may cause insomnia include:

Psychiatric conditions associated with insomnia include:

  • Depression
  • Psychosis
  • Mania
  • Anxiety, and
  • Post-traumatic stress disorder.

Sleep related disorders than can cause insomnia include:

  • Sleep apnoea
  • Sleep walking
  • Restless leg syndrome
  • Circadian sleep disturbance (i.e. timing of sleep doesn't fit with your "body clock").


Symptoms of insomnia include:

  • Difficulty falling asleep at night
  • Waking up during the night or too early in the morning
  • Not feeling well rested after a night’s sleep
  • Daytime fatigue, sleepiness, and tension headaches
  • Mood changes, including irritability
  • Poor attention and concentration
  • Anxiety and poor social function
  • Increased errors and mistakes.


Because it has many possible causes, the diagnosis and evaluation of insomnia is likely to start with a thorough medical history and a general physical examination.

The patient, and possibly their bed partner and family members, may be interviewed about the patient’s sleep history, including sleep patterns, snoring, and movement during sleep. Sleep logs or diaries may be used to record these factors on a daily basis. Taking a sleep history may also include questions about daytime performance, fatigue, concentration and attention problems, nap taking, and other common symptoms of insomnia.

A blood test may be done to check for thyroid problems or other conditions that can cause insomnia.

If your GP thinks that you could have a sleep disorder, you might be referred to a sleep specialist or sleep clinic for further assessment. A polysomnography, which is a comprehensive diagnostic test conducted in sleep clinics, may be used if sleep apnoea is suspected as the cause of insomnia.


When an obvious situational factor is the cause of insomnia, such as jet lag or work stress, removal or resolution of the cause generally cures the insomnia. When insomnia is related to a known medical or psychiatric condition, the appropriate treatment of that condition is the primary therapy for insomnia.

Otherwise, treatment of insomnia will depend mainly on the cause, and may include medical therapy, non-medical therapy (or both).

Non-medical treatments

Non-medical approaches, which mainly involve changing sleeping habits or behaviours, can be practiced at home or in combination with medical treatments and treatment for any underlying condition. These include:

  • Sleep hygiene: maintaining a regular sleep schedule, avoiding stimulating activities before bed, and having a comfortable sleep environment
  • Cognitive behavioural therapy (CBT): controlling negative thoughts or worries that keep you awake.
  • Stimulus control: techniques to help initiate sleep and create an environment that promotes sleep such as not using the bed for watching TV, eating, or other mentally-stimulating activities
  • Relaxation techniques: muscle relaxation and deep relaxed breathing to promote body relaxation and reduce anxiety at bedtime
  • Sleep restriction: limiting the time spent in bed to sleeping only and avoiding over-sleeping by not staying in bed for a long time after waking up in the morning.

Some lifestyle remedies such as vigorous daily exercise (done at least 5-6 hours before bedtime), avoiding or limiting naps, and regular practice of yoga and meditation / mindfulness can help to improve sleep.

Medical treatments

If changing your sleep habits or addressing underlying causes of insomnia do not work, prescription medications, or ‘sleeping pills’, may be used to help you to relax and sleep. Taking prescription medications for longer than a few weeks is not recommended. Many of these medications have residual effects on the following day (‘hangover’ effect) as well as the potential for abuse or addiction. They should be used with caution under the supervision of your doctor.

Sedatives and hypnotics, such as benzodiazepines (e.g. triazolam and temazepam) and non-benzodiazepine sedatives (e.g. zopiclone and zolpidem) are the most commonly used classes of medications for treatment of insomnia. Melatonin, which is a brain hormone that induces sleep, is available on prescription in supplement form for the treatment of insomnia.

Some antihistamines, e.g. promethazine and diphenhydramine, are used as sleep aids because of their sedative effects. However, insomnia is not a generally recommended use for antihistamines because of their many adverse effects and long-term drowsiness the following day.

Sedating antidepressant medications (e.g. amitriptyline and doxepin) are used successfully to treat insomnia in patients who suffer from depression.


Chawla, J. (2017). Insomnia (Web page). Medscape Drugs and Diseases. New York, NY: WebMD LLC. [Accessed: 07/05/18]
Mayo Clinic (2016). Insomnia (Web Page). Rochester, NY: Mayo Foundation for Medical Education and Research. [Accessed: 07/05/18]O’Toole, M.T. (Ed.) (2013). Insomnia. Mosby’s Dictionary of Medicine, Nursing & Health Professions (9th ed.). St Louis, MI: Elsevier Mosby.
Wilsmore B.R. et al. Sleep habits, insomnia, and daytime sleepiness in a large and healthy community-based sample of New Zealanders. J Clin Sleep Med 2013;9(6):559-66.

Updated: May 2018

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The purpose of the Southern Cross Medical Library is to provide information of a general nature to help you better understand certain medical conditions. Always seek specific medical advice for treatment appropriate to you. This information is not intended to relate specifically to insurance or healthcare services provided by Southern Cross.