What is Sleep Apnea?

What is sleep apnea?

Sleep apnea is a disorder that causes your body to stop breathing while you sleep. It’s a potentially fatal condition, with harmful short- and long-term complications, that affects more than 1 in 3 men and 1 in 6 women 1.

What causes sleep apnea?

There are three main types of sleep apnea:

Obstructive sleep apnea (OSA), which more than 80% of sleep apnea patients have, occurs when enlarged and/or relaxed throat muscles obstruct your upper airway, blocking air from entering and leaving your lungs.

Central sleep apnea (CSA), so named for its relation to the central nervous system, occurs when the brain stops signalling for the body to breathe until it detects a lack of oxygen and/or a heightened level of carbon dioxide that needs to be exhaled.

Complex sleep apnea (CompSA) is a combination of OSA and CSA. (Here are more details on the different types of sleep apnea)

Eventually your brain senses that you’ve stopped breathing and causes you to wake up just enough to gasp and start breathing again. Then you fall back to sleep and the cycle begins again. This can happen more than 120 times every hour, even though you may not remember waking up.

Short-term effects of sleep apnea

Of course apneas cause the immediate life-threatening danger of not inhaling enough oxygen (or exhaling enough poisonous carbon dioxide). But the body’s constant waking due to these apneas can also cause sleep deprivation. This can lower people’s energy and attentiveness the next day, negatively affect their moods and relationships with others, and raise the risk for memory loss, cognitive impairment and injury.

Long-term effects of sleep apnea

Untreated sleep apnea has been linked to an increased risk for other chronic and life-threatening conditions such as hypertension (high blood pressure)2 and heart failure,3 as well as poorer glucose control in patients with type 2 diabetes 4. The first step toward treating sleep apnea and living healthier is recognizing the signs and symptoms of sleep apnea and asking your doctor to get screened and tested. Roughly 80% of people with sleep apnea don’t know they have it,5 partly because they can never witness their own nighttime symptoms.

Common sleep apnea symptoms

While snoring is still the strongest predictor of sleep apnea in men and women 6 not everyone who snores has it. And more important, not everyone who has it snores. Below are other common sleep apnea symptoms:

Constant tiredness

Poor concentration

Night sweats

Weight gain

Lack of energy


Sexual dysfunction

Frequent urination at night

In addition, women often show subtler, atypical symptoms such as insomnia, morning headaches, depression and anxiety7. These symptoms often lead to misdiagnoses such as depression, insomnia or menopausal side effects 8. If you have these symptoms, be sure to ask your doctor about whether you might have sleep apnea.