What Is Sleep Apnea? A Complete Guide

September 21, 2021 | Casper Editorial Team

Fact checked by Jonathan Eilenberg, CPE

This article is for general information purposes only and is not intended as medical or other professional advice. Visit the links within the text for sources. Casper has not independently verified the sources.

What is sleep apnea? You’ve probably heard the term, and you may even suspect that you or a sleep partner or loved one has sleep apnea. Let’s explore what sleep apnea is, its symptoms and causes, and some things you can do about it in this comprehensive guide.

Keep reading to learn all about sleep apnea and how it affects you.

Sleep Apnea Definition

Sleep apnea is a potentially serious medical condition that causes you to stop breathing (apnea) or to have restricted breathing (hypopnea) multiple times during sleep. A person with sleep apnea may experience breathing difficulty hundreds of times each time they sleep. Breathing pauses usually last 10 to 30 seconds, but some linger up to a minute or more.

Left untreated, sleep apnea may deprive your brain and body of oxygen, resulting in health complications. The consequences of not getting restful sleep can also affect your quality of life. 

According to the University of Utah, 80 percent of moderate to severe sleep apnea cases go undiagnosed.

What Are the Three Types of Sleep Apnea?

There are three types of sleep apnea. Although they have different causes, their symptoms are similar.

Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) happens when the muscles at the back of your throat — which naturally become more relaxed when you sleep — collapse. This obstructs your airflow and can cause you to stop breathing entirely for a period of time. OSA is the most common form of sleep apnea.

Central Sleep Apnea

Central sleep apnea (CSA) is caused by your brain not sending the proper signals telling you to breathe. Unlike obstructive sleep apnea, which causes airway obstruction just as its name implies, central sleep apnea isn’t usually mechanical in nature. Central sleep apnea is rare and tends to affect older men more so than younger people or women. 

Complex Sleep Apnea

Complex sleep apnea (sometimes called mixed sleep apnea) is a combination of obstructive and central sleep apneas. A person with complex sleep apnea has both mechanical issues that obstruct their airway and brain misfires that impede their breathing. Complex sleep apnea is also known as treatment-emergent central sleep apnea because it can begin during treatment for obstructive sleep apnea with a positive airway pressure (PAP) or continuous positive airway pressure (CPAP) device.

NOTE: Because obstructive sleep apnea is the most common form, we’ll focus mostly on OSA in this guide. But keep in mind that the symptoms and treatment for central and complex sleep apneas are often similar.

Symptoms of Sleep Apnea

You may have heard that people with sleep apnea snore loudly. While that’s true, not everyone with sleep apnea snores, and not every person who snores has sleep apnea. So don’t rely on snoring alone as an indicator.

Here are some symptoms of sleep apnea to be aware of:

  • Loud snoring
  • Waking up gasping for air
  • Restlessness and frequent waking
  • Waking often to urinate (nocturia)
  • Morning headache
  • Dry mouth
  • Excessive unexplained daytime sleepiness
  • Mental fog and other mood disturbances like irritability or depression
  • Difficulty focusing while awake

People who have sleep apnea may not recognize the signs themselves. Instead, a bed partner often sounds the alarm because of their partner’s loud snoring. They may also notice their partner not breathing or suddenly gasping for air. If you suspect your partner may have sleep apnea, encourage them to seek medical attention.

How Common Is Sleep Apnea?

Nearly 30 million adults in the U.S. have obstructive sleep apnea. Central sleep apnea is far less common, affecting less than one percent of people in one large sleep study. People affected by central sleep apnea tended to be older males with lower body mass indexes (BMI) than those with obstructive sleep apnea. CSA sufferers may also have underlying medical conditions. 

Causes of Sleep Apnea

Knowing that you’re at risk for sleep apnea can help you decide when to consult your doctor. Some common risk factors of sleep apnea include:

  • Age: Although sleep apnea can happen at any age, the risk increases as you get older.
  • Gender: In younger people, sleep apnea is more common in men than women, but the gap between men and women affected by the condition closes as we age. By age 50, the incidence of sleep apnea is about even between males and females.
  • Type 2 diabetes: Over 80 percent of people with Type 2 diabetes suffer from unrecognized OSA. Sleep apnea can make it harder for people with diabetes to control glucose levels.
  • Obesity: Having a larger neck circumference changes the landscape of a person’s airway. Research has shown that a 10 percent increase in weight results in a six-fold increase in the incidence of sleep apnea.
  • Smoking: Inflammation in the upper airway caused by smoking can affect how the brain controls the muscles involved in breathing during sleep.
  • Alcohol consumption: Alcohol can relax the muscles around the mouth and throat, allowing the airway to become closed off.
  • Sleeping on your back: When you sleep on your back, it’s easier for the tissues around your airway to collapse and block your airflow.
  • Anatomy: Structural abnormalities like a large tongue, enlarged tonsils, or a low-hanging soft palate can contribute to sleep apnea.

Is Sleep Apnea Dangerous?

We know that having restricted airflow isn’t good, but just how dangerous is sleep apnea? An 18-year study that followed a large group of people with sleep apnea found that when left untreated, people with severe sleep apnea had a significantly higher mortality rate.

There are links between sleep apnea and heart disease, and studies have also implicated untreated sleep apnea in sudden cardiac death. Sleep apnea can also negatively affect your blood pressure.

Sleep apnea impacts the people around you, too. At home, loud snoring can disturb your bed partner’s sleep or even your entire family’s if they can hear you from a neighboring room. Disrupted sleep can also lead to irritability and even depression for you and your family members. At work, daytime grogginess causes trouble focusing, making you less productive. And if you operate heavy machinery (including automobiles), sleep apnea increases your risk of having an accident.

The good news is that your risks decrease significantly when your sleep apnea is properly treated by a medical professional.

Diagnosing Sleep Apnea: What Is STOP-BANG?

The first step in treating sleep apnea is getting a diagnosis. Clinicians use a diagnostic tool called STOP-BANG to screen for obstructive sleep apnea. It’s a acronym that stands for:

  • Snoring history
  • Tired during the day
  • Observed apnea (breathing stops while sleeping)
  • High blood pressure
  • BMI
  • Age
  • Neck circumference
  • Male gender

If sleep apnea is suspected, your doctor may recommend an overnight sleep study (or polysomnography) where your sleep and breathing are monitored in a clinical setting.

How Is Sleep Apnea Treated?

If you suspect you have sleep apnea, talk to your doctor. As we’ve already learned, sleep apnea is a potentially serious sleep disorder, so OSA and CSA should be diagnosed and treated by a professional. 

CPAP Machine

One of the first-line treatments for OSA is a continuous positive airway pressure (CPAP) machine. You wear a mask while you sleep, and the machine sends a steady stream of pressurized air to keep your airway open. The results are easier breathing, less (or no) snoring, and overall better sleep. 

Although CPAP treatment is the most common, there are other PAP devices such as the automatic positive airway pressure (APAP) machine and the bilevel or variable positive airway pressure (VPAP) machine. Your doctor will determine which device best suits your needs.

Lifestyle Changes

Lifestyle changes like weight management, eliminating alcohol and other sedative use, smoking cessation, and even training yourself to sleep on your side instead of your back all play an important role in effectively treating sleep apnea. Your doctor will discuss healthy changes you can make to help reduce OSA symptoms.

Head of Bed Elevation

For people with mild to moderate OSA, elevating the head of your bed slightly may reduce sleep apnea and promote better sleep. In one small study, researchers found that elevating the head of subjects’ beds by 7.5 degrees reduced the severity of OSA by 31.8 percent on average.

If you have mild to moderate OSA, ask your doctor whether an adjustable bed base could help with your symptoms.

Talking to Your Doctor About Sleep Apnea

Tell your doctor about any symptoms you’ve been experiencing, including daytime grogginess, mental fog, and irritability. If your bed partner, family members, or roommates have witnessed your loud and frequent snoring, let your doctor know that, too. 

Your doctor may have you take an assessment called the Epworth Sleepiness Scale to measure your daytime sleepiness, then follow up with an overnight sleep study where your sleep is monitored in a clinical setting. There, technicians will record the number of times you have restricted breathing and you’ll likely be given something called an AHI score that measures the severity of your breathing difficulty. 

If you have sleep apnea symptoms, treatment by a medical professional is the path to protecting your health and safety. 






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