Sleep disorders involve problems with the quality, timing or amount of sleep. It’s estimated that 50 to 70 million Americans chronically suffer from sleep disorders, impacting daily functioning and adversely affecting health and longevity. There are over 80 types of sleep disorders that can be grouped into the following categories:

  • Insomnia (problems falling and/or staying asleep)
  • Hypersomnia (excessive daytime sleepiness, problems staying awake)
  • Circadian rhythm disorders (problems with the pattern and/or timing of sleep)
  • Parasomnias (unusual behaviors during sleep)
  • Sleep-related breathing disorders (e.g. sleep apnea)
  • Sleep-related movement disorders (e.g. restless legs syndrome)

Common Seep Disorders

Insomnia is characterized by difficulty falling and/or staying asleep, even if you have the chance to do so.  People with insomnia usually experience one or more of the following: fatigue, low energy, difficulty concentrating, mood disturbances, and decreased performance in work or at school.  There are two types of insomnia: acute (short-term) and chronic (long-term).

Daytime sleepiness is the tendency to fall asleep during normal waking hours.  There are many causes of excessive sleepiness, and sometimes an underlying sleep disorder is responsible for making a person feel drowsy during the day, such as sleep apnea, narcolepsy, and restless legs syndrome.

Narcolepsy is a neurological disorder that causes you to be sleepy during the daytime.  When you have narcolepsy, it’s hard to stay awake and you may also proceed too quickly into dream (REM) sleep. Other symptoms include:

  • Brief episodes of muscle weakness (cataplexy)
  • Awakening with a brief feeling of the inability to move (sleep paralysis)
  • Hallucinatory symptoms (sound, sight, or skin sensations) that occur during drowsiness

Diagnosing narcolepsy can only be made by a combination of sleep studies, including a nocturnal polysomnogram (PSG) to rule out other sleep disorders and a Multiple Sleep Latency Test (MSLT) that involves multiple naps the next day.

PLMS is characterized by repetitive movements typically in the lower limbs, such as brief muscle twitches, jerking movements or an upward flexing of the feet during sleep. These episodes last anywhere from a few minutes to several hours and may cause brief awakenings during sleep, leaving a person feeling fatigued in the morning, even though he/she is unable to recall any problems during the night. It is much more common as one gets older (one-third of people over 60 have it), and it is very common in people with neurological diseases.

Sleep apnea is sleep disorder characterized by repeated stops in breathing for over ten seconds at a time.  If you have sleep apnea, you may briefly awaken few times or up to hundreds of times each night and feel tired in the morning, even though you may not recall any problems during the night.

There are two types:

  • Obstructive Sleep Apnea (OSA): A common, but potentially serious sleep disorder that impacts approximately 18 million Americans. The soft tissues of the throat partially or completely block the airway when sleeping, causing a person to snore, have pauses in breathing, and briefly awaken continually while sleeping. Men, overweight people, and people over 40 are at greater risk for sleep apnea. Untreated OSA can cause hypertension, stroke, or heart failure.
  • Central Sleep Apnea (CSA): Similar to OSA, the soft tissues of the throat partially or completely block the airway when sleeping. CSA occurs because your brain doesn’t send proper signals to the muscles that control your breathing.  It differs from OSA, where a person can’t can’t breathe normally because of upper airway obstruction due to anatomical conditions. Central sleep apnea is less common than obstructive sleep apnea.

Restless legs syndrome (RLS) affects an estimated 7-10% of the U.S. population. RLS causes unpleasant or uncomfortable sensations in the legs and an irresistible urge to move them. Symptoms typically occur in the late afternoon or evening hours, and are often most severe at night when a person is resting, such as sitting or lying in bed. They also may occur when someone is inactive and sitting for extended periods. Moving the legs or walking typically relieves the discomfort but the sensations often recur once the movement stops.

RLS can only be diagnosed with a polysomnogram (PSG) sleep study.

Additional Resources