Despite the fact the fact we sleep one third of our lives, until recently only little was known about sleep disorders. The majority of patients with sleep disorders unfortunately still remain undiagnosed. The prevalence of sleep apnea is 20 %, of which 4 % relevant. In Slovenia it is estimated that 80.000 people have breathing disorder during sleep and men predominate in a ratio of 4:1. The most common disorder is obstructive sleep apnea (OSA). Snoring is often associated with OSA, although the majority of snorers are healthy and do not have significant OSA. What is therefore necessary to be particularly attentive: to snoring, pauses of breathing during sleep (apneas), to disturbed and poor sleep as well as to daytime sleepiness. Accidents in Chernobyl, Bhopal, at Three Mile Island and also overthrowing of Challenger were officially attributed to a fatal error because of fatigue and very likely sleep disorders.

Chronically disturbed sleep , which is a regular companion of obstructive sleep apnea ( OSA ), has devastating consequences on the health, because it leads to cardiovascular disease, high blood pressure, diabetes type II, susceptibility to stroke, mental disorders, decline in sex drive or libido, obesity ...

Patients with obstructive sleep apnea are bitter, depressed, distracted and less effective.

Otherwise sleep is an active process which occurs in various stages. There are two types of sleep: rapid eye movement (REM) and non-REM (NREM) sleep. REM is 20 % and NREM 80 % of sleep. REM sleep occurs about once every 90 minutes.

NREM sleep regenerates body fatigue which appeared at the end of the day, while REM sleep relaxes the brain, processing events, memories and thoughts of the past days. This happens when we dream. Central apnea episodes are more prevalent in NREM sleep and obstructive sleep apnea are more common in REM sleep Patients with obstructive sleep apnea (OSA) usually say that they do not dream. This is because in OSA REM sleep phase is shortened due to disturbed sleep.

Adults have average of 7.5 hours of sleep per night, with the most common range of 5-9 hours per night.


If daytime sleepiness persists for a longer period of time there is a likelihood that the individual is suffering from sleep disorders. But it may also only be a symptom of sleep deprivation or too little sleep. Lack of sleep is being accumulated cumulatively; e.g. when we daily sleep one hour less than is needed for our optimum, this adds up 7 hours until the end of the week, which corresponds to a deficit of one full night.

The causes of daytime sleepiness are:

  • Lack of sleep ( acute because stay up at night or cumulative (chronic) because of prolonged sleep deprivation)
  • Shift work or work at night or very early in the morning
  • Bad habits of sleep (disregarded sleep hygiene)
  • The difference in time to travel to another time zone, usually by airplane (jet lag)
  • Abuse of or dependence on various compounds (nicotine, alcohol, drugs…)
  • Diseases such as various sleep disorders, among the most common is obstructive sleep apnea

These are the most common causes of fatigue during the day we encounter in modern society.