Sleep Apnea

An apnea is a period of time during which breathing stops or is greatly reduced. In simplified terms, an apnea occurs when a person stops breathing for 10 seconds or more. If you stop breathing completely or take less than 25% of a normal breath for a period that lasts 10 seconds or more, this is an apnea. This definition includes complete stoppage of airflow. Other definitions of apnea that may be used include at least a 4% drop in oxygen in the blood, a direct result of the reduction in the transfer of oxygen into the blood when breathing stops.

Apneas usually occur during sleep. When an apnea occurs, sleep usually is disrupted due to inadequate breathing and poor oxygen levels in the blood. Sometimes this means the person wakes up completely, but sometimes this can mean the person comes out of a deep level of sleep and into a more shallow level of sleep. Apneas are usually measured during sleep (preferably in all stages of sleep) over a two-hour period.

A hypopnea is a decrease in breathing that is not as severe as an apnea. Hypopneas usually occur during sleep and can be defined as 69% to 26% of a normal breath. Like apneas, hypopneas also may be defined as a 4% or greater drop in oxygen in the blood. Like apneas, hypopneas usually disrupt the level of sleep.

There are three types of sleep apnea:

  1. Obstructive Sleep Apnea (OSA)
    • Obstructive Sleep Apnea (OSA) occurs when the brain sends the signal to the muscles and the muscles make an effort to take a breath, but they are unsuccessful because the airway becomes obstructed and prevents an adequate flow of air.
  2. Central Sleep Apnea (CSA)
    • Central Sleep Apnea (CSA) occurs when the brain does not send the signal to the muscles to take a breath, and there is no muscular effort to take a breath.
  3. Mixed Sleep Apnea (both central sleep apnea and obstructive sleep apnea)
    • Mixed Sleep Apnea, occurs when there is both central sleep apnea and obstructive sleep apnea.

Animation provided courtesy of NHLBI.

Signs & symptoms of sleep apnea:

  • Daytime Fatigue & Sleepiness
  • Snoring
  • Insomnia
  • Anxiety
  • Memory Problems
  • Poor Concentration & Attention
  • Irritability
  • Morning Headaches

Long term health risks (associated with Sleep Apnea):

  • High Blood Pressure
  • Diabetes
  • Heart Attack
  • Stroke
  • Impotance