Types of sleep disorder

Sleep disorder 

Having trouble sleeping or sleeping too much? Getting a good night’s sleep is important for general health. Sleep problems may affect your hormone levels, mood, and weight.

This page explores the three main categories of sleep disorder. Read on to learn more about sleep problems and how to recognise different types of sleep disorder.

What is a sleep disorder?

A sleep disorder is a condition which affects how you sleep. There are three main categories of sleep disorder:

  • lack of sleep
  • disturbed sleep
  • excessive sleep

We explore the different types of sleep disorder in each category below. 

Lack of sleep

Inadequate sleep can have an immediate and noticeable effect on your mood and energy levels. But not all lack of sleep is a sleep disorder.

Insomnia is a common sleep disorder. If you have insomnia, you have trouble falling or staying asleep. Other symptoms include:

  • feeling tired in the day
  • being easily irritated
  • having trouble concentrating

Causes of insomnia include:

  • your diet
  • emotional distress
  • physical pain
  • acute, episodic acute, or chronic stress
  • an underlying health problem

Insomnia may be short-term (acute) or ongoing (chronic). If you think you may have insomnia, speak to a doctor about ways to manage this.

If an external factor is causing your lack of sleep, this is called sleep deprivation. Sleep deprivation is not a sleep disorder.

Example of external factors that may cause sleep deprivation include:

  • the hours that you work
  • your social life
  • being woken by your child

Sleep deprivation may affect your judgment, reactions, coordination, and mood.

Could you make lifestyle changes to allow you to get more sleep? If so, it is a good idea to do so. Otherwise, speak to your doctor about ways to manage sleep deprivation.

Disturbed sleep

Disturbed or disruptive sleep disorders are a category of sleep disorders that include:

  • parasomnias
  • obstructive sleep apnoea
  • periodic limb movements in sleep (PLMS)
  • circadian rhythm disorders

We explore each type of disturbed sleep below.


Parasomnias are a sub-category of disruptive sleep disorders that can lead to walking or talking in sleep. They can occur in sleep or in the transition between being asleep and awake.

Different types of parasomnia include:

  • Night terrors (also called sleep terrors): You abruptly arouse from sleep with a cry or scream. You may not remember this happening in the morning.
  • Sleepwalking: You walk around in the night, appearing to be awake, when you’re actually asleep.
  • Confusional arousals: You wake up from deep sleep, sit up, look around confused and then fall back asleep.
  • Nightmares: You have frightening, vivid dreams that may disturb your sleep.
  • Sleep paralysis: Your limbs become briefly paralysed as you fall asleep, which may be distressing.
  • REM sleep behaviour disorder: You may move your arms and legs which asleep, as if acting out your dreams.

If you think you may be experiencing a type of parasomnia, speak to your doctor. Your doctor can help to diagnose and treat your sleep disorder.

Obstructive sleep apnoea

Obstructive sleep apnoea is when your breathing pauses temporarily or becomes shallow while you are asleep. It happens when the walls of the throat relax. This interrupts normal breathing. 

Having obstructive sleep apnoea may affect the quality of your sleep. This is because pauses in breathing cause you to sleep less heavily, so your airway reopens.

You may not notice you have the condition. A partner may alert you that you may have it by telling you that your breathing is laboured in the night. If you think you may have obstructive sleep apnoea, speak to your doctor for advice.

Periodic limb movements in sleep (PLMS)

Periodic limb movements in sleep (PLMS) is a sleep disorder where you repeatedly move your limbs in your sleep. This may disrupt your sleep and cause you to be tired the next day.

PLMS normally affects the legs. If you have PLMS you may make repetitive movements with your legs every 20-40 seconds while you’re sleeping.

Speak to your doctor if you think you may have this condition. The doctor can help diagnose and treat your symptoms.

Circadian rhythm disorder

Circadian rhythm disorder is a type of disruptive sleep disorder where you find it hard to maintain a regular pattern of sleep. Your internal body clock may not work as it should.

If you have this condition you may regularly find it hard to wake up in time for work. This can disrupt your daily routine.

Shift work sleep disorder is a specific type of circadian rhythm disorder caused by shift patterns that overlap a person’s normal sleep period. 

If you think you may have a circadian rhythm disorder, speak to your doctor. The doctor can support you to manage your sleep.

Excessive sleep

Excessive sleep disorders involve sleeping too much. Getting too much sleep can affect your weight, give you headaches, and cause back pain.

Excessive sleep disorders include:

  • Hypersomnia: You are excessively sleepy and have trouble staying awake in the day.
  • Narcolepsy: A problem in your brain causes you to fall asleep suddenly and at inappropriate times in the day.

Symptoms of narcolepsy include cataplexy and hypnogogic hallucinations. Cataplexy is loss of muscle control. Hypnogogic hallucinations are hallucinations that you have while falling asleep.

If you think you may be suffering from an excessive sleep disorder, speak to your doctor. The doctor can diagnose and treat your condition.

Good Thinking recommends NHS-approved apps to help you sleep (many of which are free if you live or work in London), including:

Feeling Good (Free)

Widely used by doctors and nurses for their own benefit, the physical exercises teach solid skills that rapidly induce sleep within 2 weeks, also improving mood, reducing worry and increasing vitality.

Be Mindful (free)

A clinically proven online mindfulness course approved by the NHS, Be Mindful helps you to get better sleep through mindfulness-based cognitive therapy (MBCT).


Meditainment uses established guided meditation and visualisation techniques, leading you on imaginative journeys to dreamlike destinations to explore and reflect on a range of wellbeing topics.

tomo (free)

tomo is expertly designed to support you with many of life's obstacles, including poor sleep. The app combines digital peer support with the best of social media and proven therapeutic techniques.

Twilight (free)

An app that filters out your phone's harsh blue light to reduce eye strain and help you sleep better.

You can also use our free clinically-validated self-assessment tool to assess your sleep anonymously – it only takes 20 minutes to complete and will provide you with a guiding diagnosis, helpful resources and, if necessary, relevant treatment options.

Good Thinking sleep self-assessment

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