 Many people with EDS are unable to work, cannot enjoy formerly pleasurable pursuits such as sports and hobbies and lack the energy for even a normal intimate relationship with a spouse or significant other. Depression in people with EDS is common. 

People with EDS frequently also suffer from a condition called “microsleep,“ which is characterized by sudden, unexpected, very short mini-naps, usually lasting from as little as  1.5 seconds to 30 seconds. Microsleep is real sleep; the person is unaware of his surroundings, may actually dream, and is often disoriented upon waking. Alarmingly, most people who experience microsleep are completely unaware that they were sleeping. Microsleep can have devastating, even fatal, consequences if it occurs while driving or operating dangerous machinery. 

The causes of Excessive Daytime Sleepiness are numerous. EDS is, in fact, mostly viewed by medical experts not as a primary diagnosis, but as a symptom of other neurologic conditions, sleep disorders, metabolic diseases, and psychiatric conditions. It is also a fully amendable effect of certain life style choices such as self-imposed sleep deprivation, shift-work, or drug and alcohol abuse. 

By far the most common causes of EDS are two closely related neurologic conditions, narcolepsy and idiopathic hypersomnia. The first, narcolepsy, is a chronic neurologic condition thought to be genetic in origin, although the exact cause remains unclear. Narcolepsy usually occurs in young people; prevalence is greatest from age 10 until the early 20’s. However, it can be seen in any age group. 

Classic symptoms of narcolepsy include excessive daytime sleepiness, microsleep and a condition called “cataplexy,” a sudden loss of muscle control that can be partial (such as the drooping of the face or severe weakness of one extremity) or complete, resulting in total collapse. Cataplexy frequently occurs in conjunction with a strong emotional reaction such as laughter, surprise, or sudden, severe pain, but can happen spontaneously, for no apparent reason.   Other symptoms include periods of night time wakefulness accompanied by hot flashes, increased heart rate and an unpleasantly intense feeling of alertness or arousal, sleep paralysis and hallucinations just before falling asleep or upon waking and a characteristically unique sleep cycle during which they experience “REM” (rapid eye movement, or dream sleep) shortly after falling asleep. 


Recent research studies have shown that people who suffer from narcolepsy have a decreased amount of a substance called “hypocretin” or “orexin”–a chemical responsible for activating arousal and regulating sleep–in their cerebral spinal fluid, the protective fluid that “bathes” the brain and spinal cord. This exciting discovery led to the first definitive diagnostic test for the disorder–a simple lumbar puncture with examination of the spinal fluid–and may eventually prove instrumental in finding a treatment or even a cure for the disease.


Idiopathic hypersomnia is a disorder that is very similar to narcolepsy. The primary symptom is excessive daytime sleepiness, and microsleep is a common occurrence. Like narcoleptics, people with hypersomnia may sleep for long periods at night and nap frequently throughout the day. 