7 Types Of Sleep Disorders

If you feel exhausted during the day or are having problems sleeping better at night, you may have sleep disorders.

The collective term “sleep disorder” refers to conditions that affect the quality, timing, and duration of sleep. Following the publishing of the International Classification of Sleep Disorders – Third Edition (ICSD-3) from joint efforts of major international sleep societies, our knowledge of sleep health has drastically evolved over the past decades.

Hundreds of sleep disorders have been identified. However, most of them can be characterised by signs such as having trouble falling or staying asleep, difficulty staying awake during the day, imbalances in the circadian rhythm, and being prone to unusual behaviours that disrupt sleep.

It is quite common for people to have trouble falling asleep easily or getting quality sleep throughout the night. We typically recover from these occurrences within a short period of time. However, recurring sleep problems should be addressed as they can be symptoms of underlying health conditions.

What are the different types of sleep disorders?

Sleep Apnea

Sleep Apnea

Sleep apnea is a common chronic sleep disorder characterised by recurring episodes of complete or partial upper airway blockage during sleep, resulting in a decrease in blood oxygen levels and sleep fragmentation.

These temporary breathing lapses often lead to choking or gasping for air. Heavy snoring is a common symptom of this sleep disorder. Many cases of sleep apnea may be classified into:

  • Obstructive Sleep Apnea (OSA) – Caused by a physical obstruction that blocks the upper airway.
  • Central Sleep Apnea (CSA) – When the brain stops sending signals to the muscles that control breathing, CSA leads to choking episodes during the night.

Sleep apnea leads to deteriorated sleep quality. As with other sleep disorders, it causes excessive daytime sleepiness and fatigue, as well as various cognitive impairments and lower work performance. Lack of sleep is directly associated with health so it comes as no surprise that sleep apnea has been tied to diverse health risk factors such as stroke, heart attack, heart diseases, and hypertension.

Despite its seriousness, sleep apnea is often undetected. Early recognition is vital for appropriate therapy methods to be determined. Potential treatment of sleep apnea includes lifestyle changes (i.e., losing weight, quitting smoking), maintaining a side sleeping position, and continuous positive airway pressure (CPAP) machines to keep the airways open during sleep.


According to studies, about 10-30% of adults have some form of insomnia. It is the most common sleep disorder which refers to persistent difficulty falling or remaining asleep. Insomnia can be divided into different types, but they may occur together or separately:

  • Onset Insomnia – Difficulty in falling asleep
  • Maintenance Insomnia – Difficulty in staying asleep

Insomnia has numerous potential contributing factors and symptoms, but its diagnosis is centralised on two essential components: sleep difficulties that occur despite having opportunities for normal sleep, and daytime impairment which directly results from poor sleep quality.

To be diagnosed with chronic insomnia and separate the condition from other temporary sleep problems, you must experience the said symptoms at least three times each week and for at least three months.

Environmental (i.e, exposure to “screen” devices like computers, working late-night shifts) and physiological (i.e, chronic pain, restless leg syndrome, heart, and lung diseases) factors can play a role in triggering insomnia symptoms.

However, its most common trigger is psychological factors such as depression, stress, anxiety, bipolar disorder, excessive worrying. All these lead to an increase in heart rate, blood flow, brain activity, and release of stress hormones, which make it difficult to fall or stay asleep.

There are a variety of treatments for insomnia including medication, psychotherapy, or behavioural therapy.



Parasomnias refer to unusual behaviours that people experience before falling asleep, while sleeping, or during the period between sleep and wakefulness. The nature of parasomnia episodes varies considerably in character, severity, and frequency.

Historically, parasomnias were considered a sign of psychopathology. However, modern research argues that this sleep disorder occurs as the brain transitions in and out of sleep, as well as between rapid eye movement (REM) and non-rapid eye movement (NREM) sleep cycles. Parasomnias are more common in children, but they can occur across different age groups.

Parasomnias can generally be categorised into the following groups:

  • NREM-Related Parasomnias – NREM sleep constitutes the first stage of your sleep cycle. The most common instances of NREM-related parasomnias are incomplete awakening, limited responsiveness to people attempting to wake the sleeper, limited memory during the episode, sleepwalking, and night terrors.
  • REM-Related Parasomnias – REM sleep occurs following the first four stages of NREM sleep. This sleeping disorder is characterised by unusual vocalisations or movements often as a reaction to a dream, recurrent isolated sleep paralysis, and vivid nightmare disorder.
  • Other Parasomnias – The “other” category for parasomnias is dedicated to activities that occur during the transition between sleep or wakefulness, or during NREM/REM sleep. It is characterised by exploding head syndrome, sleep-related hallucinations, and sleep enuresis (bed-wetting).

Parasomnias are more common in children than adults, but cases have been recorded across different age groups.

Sleep Paralysis

Sleep paralysis is a sleep disorder that occurs during the REM sleep stage. During REM sleep, our body is paralyzed. This means we lose control of the voluntary muscles while involuntary muscles that control automatic responses like breathing continue to function.

When you wake and return to consciousness, your brain normally releases the body from paralysis. However, in the case of sleep paralysis, this response may be prolonged into the state of wakefulness. This results in an inability to move your body, eyelids, and even your mouth.

Within a few minutes, the paralysis should cease and body control should be regained. While sleep paralysis does not pose any worrying risks, recurring sleep paralysis may need medical help.

Periodic Limb Movement Disorder (PLMD)

Periodic Limb Movement Disorder (PLMD)

Periodic limb movement disorder (PLMD) is a rare sleep disorder characterised by periodic repetitive movements of the legs and feet during sleep. In some cases, PLMD can also affect the arms. It affects about 4% to 11% of the population. PLMD disrupts sleep, leading to daytime sleepiness and fatigue.

Treatment for PLMD may include a mix of lifestyle changes and medication, depending on the severity of symptoms. People who have PLMD may live undiagnosed for a long time because of failing to notice how it affects their sleep quality. Oftentimes, people seek treatment for this sleep disorder after the symptoms begin to interfere with their daily lives.


Narcolepsy is caused by abnormalities in the central nervous system. This autoimmune disease is characterised by excessive daytime sleepiness with sudden sleep lapses lasting 10-15 minutes at inappropriate moments (i.e, while playing sports or having conversations.

There is no known cure for narcolepsy, but medications and behavioural treatments such as taking short midday naps and practising good sleep habits help people cope with the symptoms.

Circadian Rhythm Sleep Disorder

Circadian Rhythm Sleep Disorder

People function on a 24-hour biological clock synchronised with bodily hormone production and natural light and darkness. Collectively, these sleep cycles make up the circadian rhythm.

Circadian rhythm sleep disorder is tied to dysfunctions or misalignments with the body’s internal clock. It occurs when your sleep-wake cycle interferes with daily activities.

Examples that trigger this disorder include:

  • Jet lag
  • Delayed and advanced sleep-wake disorder
  • Irregular sleep-wake rhythm disorder
  • Shift work disorder.

While symptoms for circadian rhythm sleep disorder can vary, most cause excessive daytime sleepiness and tiredness. Insomnia is also another common problem associated with this sleep disorder.

The treatment for a circadian rhythm sleep disorder may include melatonin supplements and optimising sleep environment.

Key Takeaway

The effects of sleep disorders can be highly disruptive for gaining a good quality of life. This being said, do not hesitate to communicate with your doctor to find better ways to get better sleep. Seek professional medical treatment if you think your sleep disorders are disrupting your everyday productivity.