Overview of the Most Common Types of Sleep Disorders

Sleep Apnea, Insomnia, Narcolepsy, Restless Legs, and More

Woman lying awake in bed suffering from insomnia, one of the most common sleep disorders, a group that also includes snoring, sleep apnea, narcolepsy, and others
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Many medical conditions may lead to a disruption of sleep, or an excessive amount of daytime sleepiness, and are called sleep disorders. Sleep disorders include snoring, sleep apnea, insomnia, sleep behaviors called parasomnias, restless legs syndrome, circadian disorders, narcolepsy, and others. These may be caused by physical or psychological factors.

Some of the most common types of sleep disorders include:

Snoring and Sleep Apnea

Snoring may seem benign, but it may represent a difficulty in keeping the throat open while one sleeps. Its more serious companion, sleep apnea, is a chronic medical condition where the affected person repeatedly stops breathing during sleep. These episodes last 10 seconds or more and cause oxygen levels in the blood to drop or awakenings from sleep. It can be caused by obstruction of the upper airway, resulting in obstructive sleep apnea, or by a failure of the brain to initiate a breath, called central sleep apnea. It can cause and worsen other medical conditions, including hypertension, heart failure, and diabetes and lead to serious consequences like heart attack, heart failure, stroke, and sudden death. Fortunately, effective treatments exist.

Insomnia

Insomnia is an inability to obtain a sufficient amount of sleep to feel rested and can be characterized either by difficulty falling or staying asleep.

Most people with insomnia spend more than 20 to 30 minutes falling asleep or getting back to sleep at night. If this occurs at least 3 nights per week, and lasts for at least 3 months, it is called chronic insomnia. Insomnia is the most common sleep disorder, affecting about 10 percent of adults, with many potential causes.

One of the sub-types is acute insomnia, which lasts less than 3 months, and a rare type that runs in families may even be fatal. Effective treatments include cognitive behavioral therapy for insomnia (CBTI) and the limited use of sleeping pills.

Parasomnias

From the Latin meaning "around sleep," parasomnias are sleep disorders characterized by abnormal sleep behaviors. Parasomnias involve unconscious complex, semi-purposeful, and goal-directed behaviors that have meaning or importance to the individual. These can include sleep terrors, sleepwalking, sleep eating, sleep sex, rapid eye movement (REM) behavior disorder, or any number of potential behaviors that occur while the person remains asleep. The underlying cause may be another sleep condition, such as sleep apnea, and treatments may also include safety precautions and the use of medications like melatonin or clonazepam.

Sleep Paralysis

Sleep paralysis can be terrifying! It is characterized by a temporary inability to move while transitioning from sleep to wakefulness, such as when falling asleep or waking up. It may be frightening as one may seem to be awake, but unable to move. There are often associated hallucinations. It is common, affecting about 25 percent of normal people at least once, but it also may be a symptom of narcolepsy.

Reassurance may be helpful and rarely are antidepressant medications used to decrease the frequency of the episodes.

Restless Legs Syndrome

Restless legs syndrome is a neurological movement disorder characterized by unpleasant feelings in the legs associated with a need to move. These sensations may include aches, burning, tingling, or the feeling of bugs crawling on the legs. They are improved with movement: stretching, walking, or rubbing. These symptoms may occur at rest or at night making it hard to fall asleep. RLS has many potential causes, including iron deficiency, pregnancy, and obesity.

It may be associated with periodic limb movements of sleep (PLMS). Treatments include iron replacement and medications.

Circadian Rhythm Disorders

Circadian rhythm disorders are conditions that may result when an individual’s internal biological clock is out of sync with external time cues, including the natural dark-light cycle. This may occur in total blindness, with shift work or jet lag, or due to advanced or delayed sleep phase syndrome. The mismatch may lead to insomnia or excessive sleepiness (hypersomnia) at inappropriate times. Treatments include properly timed light exposure, melatonin, and a regular sleep-wake schedule.

Narcolepsy

Narcolepsy is a sleep disorder characterized by four classic symptoms: excessive daytime sleepiness, cataplexy, sleep paralysis, and hypnagogic hallucinations. The sleepiness can be profound and may lead to falling asleep in inappropriate situations. Cataplexy is a loss of muscle tone in response to an emotional stimulus, such as surprise or laughter leading to knee buckling. Sleep paralysis is an inability to move one's body while being awake, usually while falling asleep or awakening. Hypnagogic hallucinations are vivid dream-like auditory, visual, or tactile sensations that occur while falling asleep. Narcolepsy is treated with medications, including stimulants, sodium oxybate (Xyrem), and antidepressants.

Chronic Fatigue Syndrome

Chronic fatigue syndrome (CFS) is characterized by unexplained prolonged fatigue that is not improved by rest and may be worsened by physical or mental activity. This fatigue can be severe and incapacitating, causing a substantial reduction in daily activities. It may require adaptations to conserve energy in extreme fatigue. There are a number of associated symptoms, and other medical conditions (including sleep apnea) must be excluded before CFS can be diagnosed.

Jet Lag

Jet lag is a temporary condition caused by rapid travel across time zones—as may occur with jet trips—and may leave an individual experiencing fatigue, insomnia, nausea, or other symptoms as a result of the internal circadian rhythm, or body clock, being misaligned with local time. It may be improved with the passage of time, typically 1 day per time zone traveled.

Seasonal Affective Disorder

Seasonal affective disorder is a recurrent mood disorder associated with depression and excessive sleepiness during winter months. It is caused by a lack of bright light reaching the biological clock in the suprachiasmatic nucleus, a small region of the brain. Its treatment is the use of a light box to artificially extend the day length.

A Word From Verywell

If you feel like you have symptoms of a sleep disorder, seek evaluation and treatment by a board-certified sleep physician. Effective therapy may leave you sleeping and feeling better in no time.

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Article Sources
  • Kryger, MH et al. "Principles and Practice of Sleep Medicine." Elsevier, 6th edition.
  • "The International Classification of Sleep Disorders." American Academy of Sleep Medicine, 3rd edition, 2014.