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What You Need To Know About The 3 Main Types Of Sleep Apnea

Maybe you know the feeling. You head to bed at the same time each night, ready to sleep, but every morning you wake up exhausted. Your partner might be a deep sleeper or doesn’t notice you tossing and turning, but they mention that you snore or that your breathing seems strange. If this sounds familiar, you may be one of the 25 million people in the U.S. who suffers from one of three types of sleep apnea.

What is sleep apnea?

Sleep apnea is a type of sleep disordered breathing (SDB) that occurs when the sleepers stops breathing at regular intervals during the night. These pauses in breath (referred to as apneas) are very physically taxing to the body.

There are three main types of sleep apnea:

  1. Obstructive sleep apnea
  2. Central sleep apnea
  3. Complex sleep apnea (also referred to as mixed sleep apnea)

Sleep apnea is diagnosed usually with a sleep study conducted by a sleep clinic. Your sleep lab should be accredited by the American Academy of Sleep Medicine.

After conducting a review of symptoms, the sleep clinic will hook you up to various lines and leads that measure the following:

  • Brain waves with an electroencephalogram (EEG)
  • Chin and eye movement that signals sleep stages with an electrooculogram (EOG)
  • Heart rate and rhythm with an electrocardiogram (EKG)
  • Respiration
  • Oxygen and carbon dioxide levels in the blood
  • Leg movement

The formal name of a sleep study is polysomnography. This full study takes about six hours. If polysomnography is impractical for you or your child (who is frightened of the machines), an at-home sleep study is possible. Your sleep apnea dentist may also be able to assist in a diagnosis if you present with sleep apnea symptoms during your regular dental exam.

Each type of sleep apnea is broken down below, with its common symptoms, causes, and risk factors.

What is obstructive sleep apnea?

Obstructive sleep apnea is what most people think about when they imagine someone with sleep disordered breathing.

In this type of sleep apnea, the sleeper’s throat and tongue relax during sleep and block their airway. This results in a pause in breathing before the brain alerts the sleeper and wakes them.


Symptoms of all three types of sleep apnea are very similar and include:

  • Daytime fatigue and excessive sleepiness
  • Snoring
  • Fogginess and difficulty concentrating
  • Noticeable cessation of breath followed by a choking intake of air
  • Dry mouth or sore throat upon awakening
  • Morning headache
  • Loss of sexual drive
  • Nighttime sweating unrelated to another condition (e.g., menopause)
  • High blood pressure


There is some indication that obstructive sleep apnea may be hereditary. Additionally, if you have smaller airways, it is easier for them to become blocked by relaxed throat muscles.

Risk factors

One of the main risk factors of obstructive sleep apnea is obesity. Excess fatty deposits in and around the airway are more likely to cause a blockage during sleep, especially if the sleeper is on their back.

Other risk factors include:

  • Asthma and other breathing issues
  • High blood pressure
  • Diabetes

If you snore, the likelihood that you have this type of sleep apnea increases. It’s not known if snoring causes sleep apnea or if the relationship is bi-directional, but it is a factor in diagnosis.


Obstructive sleep apnea is the most common forms, affecting approximately 22 million people in the U.S.

What is central sleep apnea?

Central sleep apnea is called that because it references activity in the central nervous system.

Breathing is an autonomous response, occurring automatically and triggered by the central nervous system. In central sleep apnea, the brain essentially forgets to signal the body to breathe.


In central sleep apnea, symptoms are similar to other types of sleep apneas. Unlike obstructive sleep apnea, central sleep apnea does not usually come with snoring, as the airway is not blocked.

If sleep apnea is caused by a neurological disorder, the sleeper may also have difficulty swallowing and feel numbness and weakness. They may also notice changes in their voice.


Central sleep apnea usually occurs when there is an injury or trauma to the brain stem, the area where the order to breathe comes from. Other causes include:

  • Parkinson’s disease
  • Chronic heart failure
  • Degenerative arthritis in the spine

Risk factors

People with neurological disorders or injuries to the brain or brainstem are most at risk.


It is challenging to identify exact statistics on this type of sleep apnea. Some believe that fewer than 1% of sleep apnea sufferers are diagnosed with this form, while others think the number is closer to 20%.

What is mixed sleep apnea?

Mixed sleep apnea (complex sleep apnea) was first identified in 2006 by the Mayo Clinic. They observed obstructive sleep apnea in patients that was unrelieved by treatment and determined that central sleep apnea was also present.


The symptoms of mixed sleep apnea are the same as the others in general. Breathing stops up to 20 to 30 times an hour before the sleeper gasps a choked intake of air. The difference here is that sleepers do not get relief from a CPAP machine but continue to have issues with breathing all night long.

Sleepers with complex sleep apnea also do not report waking up as often as those with central sleep apnea.


While the causes for obstructive sleep apnea are similar when it presents in complex sleep apnea, there is no clearly identified cause for both obstructive and central sleep apnea to occur.

It is unclear what causes a person to suffer from two types of sleep apnea concurrently.

Risk factors

Risk factors of complex sleep apnea are similar to those with obstructive sleep apnea. The profile of a mixed sleep apnea patient is similar to that of an obstructive sleep apnea patient in terms of cardiovascular health.

Men are diagnosed with complex sleep apnea more often than women, perhaps due to the difference in respiratory control (men’s is less stable).

Other than that, there are no clearly identified risk factors for this type of sleep apnea.


Complex sleep apnea seems to be found in 15% of all patients diagnosed with sleep apnea.

Treating the different types of sleep apnea

Treatment for all three types of sleep apnea is crucial, as the condition can have serious (and even fatalhealth risks. The most common treatments for obstructive sleep apnea include:

For sleepers with central sleep apnea or complex sleep apnea, treating the underlying condition is the first-line strategy.

AZ Sleep is your sleep apnea dentist, with offices in Phoenix and all over the Valley. We know about all three types of sleep apnea and can help you move towards a good night’s sleep. Get in touch today!

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