What Is A Clear Airway Apnea?

clear airway apnea

If you have looked at your CPAP machine and noticed a CA code, you may be wondering what that means. While most of us suffering from sleep apnea experience some form of obstruction, some apneas develop and happen without obstruction. This is known as clear airway apnea and is not as common as some other sleep apnea types.

How Do I Know I Have A Clear Airway Apnea?

To be diagnosed with clear airway apnea, you will need to be tested with the Apnea-Hypopnea Index to determine the severity and type of apnea that you have. When your breathing stops for more than 10 seconds during this test, the AHI will mark the event and determine how often this happens in an hour. With each event, the denaturation of your blood oxygen level is recorded.

Based upon how many events you have in an hour compared to your blood denaturation levels, that will determine the severity of the apnea. During this test, if the pressure maintains a great flow, there is no obstruction, and the apnea is considered clear airway apnea.

Is There More Than One Type of Clear Airway Apnea?

Once it is determined you have clear airway apnea, you should know what type you are experiencing. You can have either central sleep apnea or complex sleep apnea, which develops for many reasons.

Central Sleep Apnea

Of these two kinds, central sleep apnea is more common for those who have no obstructions and still experience apneas regularly while sleeping. Your respiratory movements are restricted when you are sleeping, directly correlating to your brain and how it functions. You can be laying comfortably with your respiratory system breathing steadily, and then your brain stops sending signals to breathe.

It is almost as though it forgets to breathe for a period of time until the oxygen loss in your body sends a response to the brain, and new signals are released at that time. In most cases, this takes well over 10 seconds.

In most cases, healthy individuals do not experience central sleep apnea. This is often related to individuals who are experiencing an illness affecting the brain stem. Spinal injuries in the lower brain stem or neck can impact the brain’s function and allow it to ‘forget’ to send breathing signals when you are sleeping.

Newborns with underlying conditions sometimes experience these pauses at double-time, nearly 20 seconds of their brain not allowing them to respond.

Causes of Central Sleep Apnea

If you have been diagnosed or think you may be experiencing central sleep apnea, several causes are related to your breathing is disrupted. One of the most common causes found in cases is lack of sleep or irregular sleep patterns where the body cannot rest constantly or consistently. During these periods, your brain stem and functions work without rest for longer periods of time, allowing the brain to pick and choose the most important functions.

In other cases, the carbon dioxide levels in your body start to fluctuate, changing up and down, and adversely impacting your brain function. While your body has the physical ability to breathe, it is not commanded to do so.

Complex Sleep Apnea

This type of clear airway apnea develops in those who were once diagnosed with obstructive sleep apnea and received treatment. While the obstruction may no longer be there and has been treated with the CPAP machine, central sleep apnea develops and takes the place of the previously obstructive sleep apnea. Even those who are just getting treatment for their obstructive sleep apnea, in the beginning, may experience times when complex sleep apnea develops.

The majority of all cases of complex sleep apnea seem to develop using a CPAP machine, and there are some cases where certain individuals develop this apnea. Those who suffer greatly from insomnia and restlessness seem to develop periods of complex sleep apnea. This is not ongoing like other apneas that can last for long periods and require extensive treatment.

Sometimes, complex sleep apnea can be resolved with pressure changes and necessary readjustments on the CPAC machine. The most important way to treat complex sleep apnea, however, is time.

Signs You May Be Experiencing Clear Airway Apnea

If you have not been diagnosed with sleep apnea or do not have any obstructive sleep apneas, then you could be suffering from one of the clear airway apnea types.

Daytime Drowsiness

This is more than just the afternoon blues. Excessive daytime drowsiness or sleepiness means that you have difficulty staying awake or alert throughout the day. You may find that you are napping more frequently than before, although you are not anymore active than you have been or have not had any changes in your diet.

Disruptive Sleep

Those who suffer from central sleep apnea find themselves waking up frequently through the night. It isn’t easy to get a full night’s sleep, and you cannot get through your sleep cycle. Oftentimes, these disruptions where you awaken suddenly are related to an apnea episode. Depending on how frequently your sleep is disrupted, daytime drowsiness could be significant for you the next day.


If you discover that you are snoring or hearing it from a loved one experiencing it, you definitely need to schedule a sleep study. When we snore, it means that there is either an obstruction or a reaction to the body not being able to breathe properly. If snoring is something you do almost every day, something else impacts your breathing when you sleep.

These symptoms are indicators that you are suffering during your sleep, and you can get treatment. The only way to know if you have one of the two types of clear airway apnea is to have a sleep study conducted and assessed by your doctor. The AHI pressure can determine what is causing your apnea and the best way to treat it moving forward.


Dan was diagnosed with sleep apnea in 2017 when he was only 32 years old. He has been using a BIPAP machine for his treatment. He hopes to provide a patient's perspective on the sleep apnea experience. Dan lives in Tampa with his girlfriend and 2 dogs.

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