Causes of insomnia

Insomnia can be triggered by a number of possible factors, including worry and stress, underlying health conditions, and alcohol or drug use.

Sometimes it's not possible to identify a clear cause.

Stress and anxiety

Some people develop insomnia after a stressful event, such as a bereavement, problems at work, or financial difficulties.

The problem can continue long after the event has passed because they start to associate going to bed with being awake. This develops into an anxiety about sleep itself.

Having more general worriesfor example, about work, family or healthare also likely to keep you awake at night.

These can cause your mind to start racing while you lie in bed, which can be made worse by also worrying about not being able to sleep.

Poor sleep routine andsleeping environment

You may struggle to get a good night's sleep if you go to bed at inconsistent times, nap during the day, or don't "wind down" before going to bed.

A poor sleeping environment can also contribute to insomniafor instance, an uncomfortable bed or a bedroom that's too bright, noisy, hot or cold.

Lifestyle factors

Drinking alcohol before going to bed and taking certain recreational drugs can affect your sleep, as can stimulants such as nicotine (found in cigarettes) and caffeine (found in tea, coffee and energy drinks). These should be avoided in the evenings.

Changes to your sleeping patterns can also contribute to insomniafor example, because of shift work or changing time zones after a long-haul flight (jet lag) .

Mental health conditions

Underlying mental health problems can often affect a person's sleeping patterns, including:

  • mood disorders such as depression or bipolar disorder
  • anxiety disorders such as generalised anxiety , panic disorder or post-traumatic stress disorder
  • psychotic disorders such as schizophrenia

Physical healthconditions

Insomnia can also be caused by underlying physical conditions, including:

  • heart conditions such as angina or heart failure
  • respiratory conditions such as chronic obstructive pulmonary disease (COPD) or asthma
  • neurologicalconditions such as Alzheimer's disease or Parkinson's disease
  • hormonal problems such as an overactive thyroid
  • joint or muscle problems such as arthritis
  • problems with the genital or urinary organs such as urinary incontinence or an enlarged prostate
  • sleep disorders such as snoring and sleep apnoea , restless legs syndrome , narcolepsy , night terrors and sleepwalking
  • long-term pain

In women, childbirth can sometimes lead to insomnia.


Some prescriptions or over-the-counter medications can cause insomnia as a side effect.

These include:

  • certain antidepressants
  • epilepsy medicines
  • medicines for high blood pressure , such as beta-blockers
  • steroid medication
  • non-steroidal anti-inflammatory drugs (NSAIDs)
  • stimulant medicines used to treat attention deficit hyperactivity disorder (ADHD) or narcolepsy
  • some medicines used to treat asthma, such as salbutamol, salmeterol and theophylline

Check the leaflet that comes with any medication you're taking to see if insomnia or sleeping difficulties are listed as a possible side effect.

Content supplied by the NHS Website

Medically Reviewed by a doctor on 24 Nov 2016