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What is Sleep Apnea?

What is Sleep Apnea?

Obstructive sleep apnea is a sleep disorder breathing caused by relaxed pharyngeal muscles collapsing into the airway during sleep. The patient will snore, stop breathing, and awaken a little, then fall asleep again. This lack of sleep and oxygen leads to a sense of exhaustion.

The patient may not know they suffer from sleep apnea because 80% of the people with the condition are believed to be undiagnosed.

There are three types of sleep apnea:

  • Obstructive sleep apnea (OSA) – the most common - where relaxation of the pharyngeal muscles interferes with the airway, causing breathing to stop.
  • Central sleep apnea – not as common as OSA - where the brain or nerves fail to trigger the breathing muscles to breathe.
  • Mixed sleep apnea - where a central Apnea is followed by an obstructive apnea.

Relative severities of sleep apnea

Normal Fewer than 5 interruptions   per hour.
Mild sleep apnea Between 5 and 15 interruptions per hour.
Moderate sleep apnea Between 15 to 30 interruptions per hour.
Severe sleep apnea More than 30 interruptions per hour.


Affected populations

Sleep apnea occurs in all age groups and body morphologies but several factors can dramatically increase the chances:

  • Obesity – around 77% of obese patients suffer from sleep apnea.
  • Sleep apnea is more likely in people between 50-60 years.
  • Thyroid conditions or a goiter that constricts the neck or airway.
  • Physical characteristics of the throat such as enlarged tonsils, a small airway, or small nasal passages.
  • Ingestion of alcohol, sedatives or sleeping pills before bed.


Generally, symptoms of Obstructive sleep apnea begin insidiously and are often present for years before the patient is referred for evaluation.

Nocturnal symptoms may include the following:

  • Snoring, usually loud, habitual, and bothersome to others.
  • Witnessed apneas, which often interrupt the snoring and end with a snort.
  • Gasping and choking sensations that arouse the patient from sleep, though in a very low proportion relative to the number of apneas they experience.
  • Nocturia.
  • Insomnia; restless sleep, with patients often experiencing frequent arousals and tossing or turning during the night.

Daytime symptoms may include the following:

  • Nonrestorative sleep (ie, “waking up as tired as when they went to bed”).
  • Morning headache, dry or sore throat.
  • Excessive daytime sleepiness that usually begins during quiet activities (eg, reading, watching television); as the severity worsens, patients begin to feel sleepy during activities that generally require alertness (eg, school, work, driving).
  • Daytime fatigue/tiredness.
  • Cognitive deficits; memory and intellectual impairment (short-term memory, concentration).
  • Decreased vigilance.
  • Morning confusion.
  • Personality and mood changes, including depression and anxiety.
  • Sexual dysfunction, including impotence and decreased libido.



Co-morbidities of sleep apnea include:

Poor cardiovascular health  Hypertension 
Stroke  Type 2 diabetes 


All about Sleep Apnea

Learn more about Sleep Apnea