Excessive Sleepiness


Excessive sleepiness can arise for several basic reasons: poor quality sleep, impaired brain wakefulness mechanisms, or both.

  • Most cases of excessive sleepiness arise from poor quality sleep due to breathing problems (SLEEP APNEA and UPPER AIRWAY RESISTANCE SYNDROME).

-It is our feeling that the reason why so many patients with sleep-related breathing disorders develop sleepiness is the fact that they must struggle repeatedly to overcome throat collapse. They work hard all night to breathe and are left exhausted.

-If severe sleepiness either begins or progressively worsens in adulthood (particularly if snoring or obesity are present, but even if not!)–suspect SLEEP APNEA first! Sleep apnea is extremely widespread (has been reported in up to 24% of men and 9% of women, who tend to “catch up with the men” in terms of sleep apnea prevalence.

-It also has been our impression that many women do not snore as loudly as men, and studies have shown that sleep related breathing problems are especially likely to go undiagnosed in women.

  • Impaired brain wakefulness mechanisms are relatively common and often result from abnormalities in brain chemicals (neurotransmitters) involved in maintaining alertness.

-These disorders of brain chemical abnormalities causing sleepiness begin most often before age thirty, although there are exceptions. Hence, two clues to their presence are development of sleepiness before age 30, and sleepiness that preceded any significant snoring.

Sleepiness in children and teenagers can also reflect SLEEP APNEA, but in the absence of snoring and factors that make it more difficult to breathe (such as large tonsils and adenoids or nasal congestion), impairment of brain wakefulness mechanisms should be considered.

-The most prevalent disorder of brain chemistry causing sleepiness is NARCOLEPSY.

It is important to understand that it is not true that narcoleptics have abrupt attacks of sleep and are normal between sleep attacks. Narcoleptics are chronically sleepy people, prone to falling asleep at times that normal individuals might simply feel a bit drowsy–and narcolepsy comes in all degrees of severity.

Narcoleptics are at increased risk of developing sleep apnea later in life, such that they ultimately may suffer from two concurrent causes of excessive sleepiness.

-Another diagnostic category is IDIOPATHIC CNS HYPERSOMNIA: which is a diagnosis by exclusion. It refers to patients with brain sleepiness not resulting from sleep related breathing disorders, narcolepsy or other identifiable causes. In other words, one must exclude/ “rule out” all other possible causes of excessive sleepiness before this diagnosis can be given. There is no specific test for idiopathic hypersomnia.

Idiopathic hypersomnia is significantly less common than narcolepsy. It is not nearly as common as we once thought.

Many patients who are incorrectly given the label of idiopathic hypersomnia actually have subtle sleep-related breathing disorders! One example: UPPER AIRWAY RESISTANCE SYNDROME (UARS), which is easily missed by conventional sleep center monitoring techniques. Also, patients with UARS often do not snore much. UARS is particularly common in slender individuals, in women and in children. And it is easier to treat than idiopathic hypersomnia.

If you or a loved one has been given the diagnosis of idiopathic hypersomnia, it is important to ensure that all other possible diagnoses were ruled out and that the sleep center specifically looked for and excluded UARS!

-Also, always consider such factors as inadequate sleep and the many medications that can cause sleepiness–including many over the counter drugs such as antihistamines and even some health food preparations! At the same time, though, if sleepiness is severe, sleep-related illnesses must not be overlooked. They are common, frequently serious, and usually treatable.

Indications of Excessive Sleepiness

It is important to realize that sleepiness is usually underestimated by the person with the problem!

-Sleepiness at the wheel is much more likely to cause deaths and severe injuries than either heart attacks or convulsions occurring while driving. The latter two problems usually cause warning symptoms that allow the person to “pull over”. In contrast, sleepy drivers usually do not sense their impairment. The result: high speed crashes with no attempt to brake.

-For this reason, if others think you are too sleepy and you disagree, odds favor their being correct. You should heed their concerns!

When people with pathologic sleepiness do not sense it, what symptoms might they notice instead?

  • Poor memory and/ or confusion. Many sleepy individuals fear that they are developing Alzheimer’s disease.
  • Irritability; depression.
  • Worsening job performance.
  • Inefficiency and mistakes.
  • “Automatic behavior”. Performance of activities, including driving, on “autopilot” with inability to recall details of what happened during those activities.
  • Attention deficit symptoms suggesting ADD/ADHD.


How To Arrive At a Diagnosis

A CAREFUL HISTORY SHOULD COME FIRST!  –  and it should involve:

  • Analysis of specific symptoms, such as those related to disturbances of REM sleep.
  • Looking for possible life events, medications, other illnesses and any other factors that may have been factors in causing or aggravating the problem.

A PHYSICAL EXAMINATION SHOULD BE PERFORMED. Specific abnormalities should be sought that could help identify the likely cause of the person’s sleepiness.

CERTAIN DIAGNOSTIC TESTS ARE SOMETIMES HELPFUL. For example, exclusion of abnormal thyroid function is important, since hypothyroidism (which can cause or worsen sleepiness) is both common and treatable.


  • In all cases, monitoring of overnight sleep (polysomnography) is important: to look for a wide variety of possible factors that could be making sleep ineffective. Sleep stages, breathing, heart rhythm and leg movements are among the most basic parameters routinely measured, and a number of additional body functions should be evaluated concurrently if warranted.
  • Particularly if the individual’s sleepiness has arisen not from disturbed sleep, but instead, from abnormalities in brain mechanisms responsible for maintaining alertness, an additional test (the multiple sleep latency test or MSLT) is performed. It involves monitoring of four or five brief nap sessions during the day following an overnight polysomnogram: to determine how rapidly the patient falls asleep, and to look for the inappropriate occurrence of REM sleep in multiple naps (which can suggest narcolepsy and other causes).

Sleep center studies are safe to the point they can even be done in small infants!–and the amount of valuable information that they provide is often astounding. They frequently are the essential keys to resolving serious problems of impaired alertness.

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