Four Major Sleep Disorders

Joseph R. Anticaglia MD
Medical Advisory Board

Sleep, like food, is a basic human necessity. In 2020, the U. S. Census Bureau counted 258.3 million adults living in the United States. A startling “one third of U. S. adults report that they usually get less than the recommended amount of sleep,” says the CDC. Long term inadequate sleep (less than seven hours of sleep) adversely affects a person’s mood, attentiveness, performance and health. Such sleep deprivation has been correlated with diabetes, depression, cardiovascular disease and obesity.

Four Major Sleep Disorders:

  1. Insomnia — difficulty in falling and/or staying asleep.
  2. Sleep Apnea — irregular breathing pattern while sleeping.
  3. Restless Leg Syndrome — uncontrollable urge to move the legs.
  4. Narcolepsy — brief, sudden attacks of excessive daytime sleepiness.

1. Insomnia

Insomnia occurs when a person has trouble in falling asleep and/or staying asleep, or early wakefulness and not being able to get back to asleep. Occasionally, you’ve probably have had nights when you couldn’t fall asleep. These short term episodes of difficulty with sleep, acute or transient insomnia, last a few days or weeks and are usually of little importance. Stress, caffeine, daytime napping, early bedtime, jet lag and physical discomfort are factors that contribute to this problem.

Chronic or persistent insomnia is difficulty falling and/or staying asleep three times a week lasting three months or more. The following are other factors that cause insomnia:

  • Mental problems, such as depression and manic disorders are often associated with insomnia
  • Nicotine abuse (smoking more than a pack of cigarettes per day)
  • Alcohol abuse
  • Medications
  • Anxiety and stress
  • Medical conditions, for instance, breathing disorders, thyroid problems, conditions causing chronic pain, sleep apnea, restless leg syndrome and narcolepsy.

2. Sleep Apnea

Sleep apnea is a sleep disorder in which a person’s breathing stops and starts for ten seconds or more many times during the night while sleeping. Most patients are obese, middle aged men, at times, with a “bull neck.” These people experience periodic loud snoring and periods of gasping for air or breathing pauses as witnessed by one’s bed partner. It can happen five or more times per hour.

What happens during sleep is that there’s a loss of pharyngeal muscle tone, the muscles in the back of the throat relax and collapse, causing upper airway obstruction and preventing oxygen reaching the lungs. When the blood oxygen level falls to a certain level, the brain responds by awakening the person that leads to restoring muscle tone and breathing. Certain conditions predispose one to sleep apnea, such as nasal obstruction, large tonsils (tonsillar hypertrophy) large tongue (macroglossia) and an undersized jaw (micrognathia).

3. Restless Leg Syndrome (RLS)

RLS is an uncontrollable urge to move the legs. This condition usually occurs in the evening, for example, when your sitting watching TV, or when you’re lying down in bed. The leg movements are temporarily relieved by getting up and moving around.

Lynn, a 57 y/o advertising executive, is bothered by occasional uncontrollable leg twitching while sitting at her desk while working late in the evening. It became worrisome when the leg movements interfered with her sleep. She sought the advice of a sleep specialist.

She told the doctor that “Inside my legs, I feel as if the nerves are crawling. And I must move my legs to get relief.” After laboratory blood work, the doctor explained that she has a type of anemia in which her body was not storing enough iron (ferritin level was low). She was prescribed iron supplements which resolved her restless leg complaints.

RLS can occur at any age, but is most common in the elderly. Besides iron deficiency anemia, this condition has been linked to pregnancy, Parkinson’s disease and peripheral neuropathies (diabetic or uremic).

4. Narcolepsy

Narcolepsy consists of brief attacks of excessive daytime sleepiness combined with sudden muscle weakness (loss of muscle tone). This disorder may cause a person to suddenly slump on a table, or to the floor unable to move. The attacks last about 15 minutes and may occur during any type of activity. The person may experience visual or auditory hallucinations immediately before falling asleep, or during the attack.

Stock photo: Man, asleep at the wheel

Narcolepsy starts early in adult life, may run in families and affects both sexes equally. Researchers aren’t sure what causes narcolepsy, but they found low levels of hypocretin, also called orexin, in people with this disorder. Orexin is a chemical that helps you stay awake.

Chronic sleep disorders affect millions of Americans. Timely diagnosis and treatment can improv a person’s alertness, performance and decrease the risk for accidents.


  1. National Institute of Neurological Disorders and Stroke, Brain Basics: Understanding Sleep
  2. CDC; Sleep and Sleep Disorders
  3. Joseph R. Anticaglia, MD; Remarkable Sleep Understanding How Sleep Works REM a Non-REM Sleep; HC Smart, 2022
  4. Sleep Medicine; Consequences of Insufficient Sleep; Sleep Medicine at Harvard Medical School
  5. Insomnia Cleveland Clinic, October 15, 2020


Cataplexy — the sudden loss of muscle tone while a person is awake which leads to loss of voluntary muscle control.

This article is intended solely as a learning experience. Please consult your physician for diagnostic and treatment options.