Mercy Regional Health Center

Types of Sleep Apnea

Apnea is the cessation of breathing. In sleep medicine, sleep apnea is identified through an overnight polysomnogram by tracking each time that airflow stops for at least 10 seconds with a drop in oxygen level or an arousal from sleep.

A less severe reduction in airflow is called a hypopnea. Unlike an apnea where no airflow is detected, there is airflow during hypopneas, however it is significantly reduced. Like apneas, hypopneas must be ten seconds or greater in length and associated with a decrease in oxygen level or an arousal from sleep.

Sleep apnea is divided into three categories:

Central Sleep Apnea
Central sleep apnea is when the brain intermittently fails to send a signal to the lung muscles that it's time to breathe. Consequently, the lungs make no attempt to breathe, and no air flows into the lungs. Central sleep apnea is primarily the result of a neurological issue, such as a stroke or drug use.

Central sleep apnea is generally treated with:

  • Medications
  • Positive airway pressure (Bi-level PAP)


Obstructive Sleep Apnea (OSA)
Obstructive sleep apnea (OSA) is when air flow is intermittently prohibited from entering the lungs by an obstruction in the airway — even though the chest and abdominal muscles continue to try to take a breath. The obstruction is generally in the back part of the throat, making you struggle to take a breath against this obstruction. These efforts continue increasing in strength until finally there is enough force to overcome the obstruction. When airflow resumes, there is often a loud snore or snort, one of the hallmarks of OSA. Obstructive sleep apnea is the most common form of sleep apnea.

OSA affects 2% to 4% of pre-menopausal women and 6% to 8% of men. The incidence for post-menopausal women is very similar to men. Although not considered hereditary, OSA can be seen in families due to environmental situations as opposed to genetic links.

Signs and symptoms of obstructive sleep apnea include:

  •  Excessive daytime sleepiness
  •  Fatigue
  •  Snoring
  •  Irritability

Untreated, OSA can result in very serious consequences, such as:

  •  Motor vehicle or work-related accidents
  •  Heart disease
  •  High blood pressure
  •  Sexual dysfunction
  •  Stroke
  •  Death

OSA is also linked to or complicates:

  •  Attention deficit/hyperactivity disorder (ADD/ADHD)
  •  Type II diabetes

Learn more about OSA treatment options.


Mixed Sleep Apnea
As the name suggests, mixed sleep apnea is a combination of central sleep apnea and obstructive sleep apnea. Generally, there is no signal from the brain to breathe at the beginning of the apnea, resulting in no effort and no airflow. Then, in the midst of the central apnea, the brain kicks in and respiratory effort starts, but by this time the airway is obstructed due to relaxation of the soft tissue in the airway. The result is obstructive sleep apnea.

Mixed sleep apnea is generally treated with continuous positive airway pressure (CPAP).


For more information on sleep apnea, or any other sleep disorder, contact us.