What’s the difference between mild, moderate and severe sleep apnea?
Sleep specialists decide if your sleep apnea is mild, moderate, or severe by counting how many times your breathing stops each hour. The times when your breathing stops are called “apneas” or “events”. They can count these events using polysomnography or portable home monitoring.
- 5 to 15 events per hour : Mild sleep apnea
- 15 to 30 events per hour : Moderate sleep apnea
- over 30 events per hour : Severe sleep apnea
There are other things doctors consider when they are deciding how severe your sleep apnea is. Some other considerations are:
- How sleepy you feel
- How low your oxygen level dips
- How long your oxygen level stays below 90%
- Other medical conditions you may have, such as heart disease
What is central sleep apnea?
In central sleep apnea, your brain forgets to tell your muscles that you need to breathe. Your throat and airway are normal- it’s your brain that has the trouble. Central sleep apnea is not as common as obstructive sleep apnea. Often people with central sleep apnea have another medical condition, such as heart failure. Treating their other medical condition can improve the central sleep apnea. Some newer devices may improve central sleep apnea.
It is possible to have both obstructive and central sleep apnea. This is called mixed sleep apnea.
What is sleep-hypoventilation syndrome?
When a person doesn’t breathe enough during the day and night to take in the oxygen they need, this is called is called Sleep-hypoventilation syndrome. Hypoventiation means to breathe less than is necessary to keep the levels of oxygen and carbon dioxide in the blood normal. Sleep Hypoventilation is linked to obesity.
The first choice of treatment for sleep-hypoventilation syndrome is continuous positive airway pressure (CPAP). If a person’s oxygen and carbon dioxide levels don’t improve with CPAP, the doctor will recommend a more sophisticated machine, like a bilevel positive airway pressure (BiPAP) machine.
What is Mixed or complex sleep apnea?
In Mixed or Complex sleep apnea a person has a blend of both central and obstructive sleep apnea. Each episode usually begins when your brain forgets to tell your muscles that you need to breathe (central sleep apnea). Then your body tries to breathe, but the airway is blocked (obstructive sleep apnea).
How common is sleep apnea?
- 1 of every 5 adults has at least a mild form of sleep apnea (20%)
- 1 of every 15 adults has at least moderate sleep apnea (6.6%)
- 2 to 3% of children are likely to have sleep apnea
- Over 1 in 4 (26%) Canadian adults have a high risk of having or developing obstructive sleep apnea.
What is Mixed or complex sleep apnea?
In Mixed or complex sleep apnea a person has a blend of both central and obstructive sleep apnea. Each episode usually begins when your brain forgets to tell your muscles that you need to breathe (central sleep apnea). Then your body tries to breathe, but the airway is blocked (obstructive sleep apnea).
I have sleep apnea. Is it safe to travel?
Yes, it’s safe for people with sleep apnea to travel, as long they continue their treatment. Sleep apnea does not take a vacation. You need to take your CPAP with you when you travel.
If you are flying, bring your CPAP machine as carry-on luggage. To make getting through security as smooth as possible, bring a letter from your doctor explaining what your CPAP machine is, and that it’s medically necessary for you to use it.
The letter from the doctor should say:
- That your CPAP equipment is required for a medical condition.
- The model (e.g. ResMed S7 Elite) and the serial number of all your equipment
Check about the type of electrical supply in the country where you are traveling. You may need a converter. You may also want to bring a battery pack.
You should bring your CPAP with you everywhere you sleep. If you go to the hospital, bring your CPAP machine and use it.
You may also want to read our FAQs on CPAP treatment.
This content was reviewed on October 15th, 2014 by The Canadian Thoracic Society's Sleep Disordered Breathing Clinical Assembly.