What is Sleep Apnea?

Quick Overview

Sleep apnea is a common sleep disorder in which breathing repeatedly stops or becomes shallow while you sleep. If you’ve typed “what is sleep apnea” into a search bar because of a partner’s snoring or your own daytime exhaustion, you’re not alone: a national health survey found that 22% of adult Canadians, roughly 5.4 million people, either have been diagnosed with sleep apnea or show signs that put them at high risk for it. Because untreated sleep apnea is linked to heart disease, high blood pressure, cardiovascular disease, and metabolic syndrome, getting a proper diagnosis isn’t just about better sleep. Of all the sleep disorders a healthcare provider might screen for, sleep apnea is one of the few with such a direct line to your heart and metabolic health, which is exactly why it’s a step toward protecting your long-term health, not just your mornings.

What Is Sleep Apnea

Understanding what sleep apnea is starts with the basics: at its core, it’s a condition in which your breathing is repeatedly interrupted while you sleep. Doctors describe it as a type of sleep-disordered breathing, and the interruptions fall into two categories. An apnea is a near-complete pause in breathing, usually lasting at least ten seconds. A hypopnea is a partial reduction in airflow that still lowers the oxygen reaching your blood, even though you’re technically still breathing. Both count toward how healthcare providers measure the severity of sleep apnea, and both can happen dozens or hundreds of times a night without you ever fully waking up.

Because these pauses fragment your sleep cycle, the effects show up the next day. People with sleep apnea often describe grogginess that coffee doesn’t fix, trouble concentrating at work, irritability, and a strong urge to nap in the afternoon. Over time, this daytime sleepiness can affect everything from job performance to driving safety, which is one of the biggest reasons healthy sleep matters just as much as the number of hours you spend in bed.

Is It Sleep Apnea Or Just Snoring?

Plenty of people snore without having sleep apnea, so it’s a fair question to ask before diving into what is sleep apnea versus what’s simply a noisy night. Occasional snoring, on its own, usually doesn’t come with breathing pauses, gasping, or next-day exhaustion. Sleep apnea is different: it’s one of several sleep disorders that specifically involves repeated interruptions to breathing, not just sound. If snoring is loud and constant, and especially if it’s paired with witnessed breathing pauses or morning grogginess, it’s reasonable to ask a healthcare provider whether sleep apnea, rather than ordinary snoring, is the more likely explanation.

Types Of Sleep Apnea

Not all sleep apnea looks the same. There are three main types of sleep apnea, and each differs in what’s actually stopping your breath, with its own set of warning signs. Among sleep disorders that affect breathing, understanding which type you’re dealing with shapes everything from home care to how a specialist will approach treatment.

Obstructive Sleep Apnea

Obstructive sleep apnea, often shortened to OSA, is by far the most common form of sleep disorder in this category, and it’s what most people picture when they hear the term sleep apnea. It happens when the soft tissues at the back of your throat relax too much during sleep, letting the upper airway partially or fully collapse. Air simply can’t get through the way it should until the airway opens again, often with a gasp or snort. Mild to moderate obstructive sleep apnea can develop gradually, which is part of why so many cases of obstructive sleep apnea go unnoticed for years.

The clearest sign of obstructive sleep apnea is loud, persistent snoring, especially when a sleeping partner reports pauses in your breathing followed by gasping or choking sounds. Other clues include waking up with a dry mouth or a headache, and feeling exhausted no matter how many hours you spent in bed. If a bed partner has mentioned any of this, it’s worth taking seriously rather than brushing it off as “just snoring.” Mild obstructive sleep apnea can be easy to miss, since snoring alone doesn’t always feel alarming.

Central Sleep Apnea

Central sleep apnea works differently. Instead of a physical blockage, it happens when the brain fails to send the right signals to the muscles that control breathing. The brain essentially misses a beat, the airway stays open, but the drive to breathe temporarily switches off.

Central sleep apnea is a much less common form than the obstructive type and is more often linked to underlying conditions such as heart failure, stroke, or certain neurological disorders, as well as some medications. People with heart failure or a history of stroke are more likely to develop central sleep apnea than the general population. Because the root cause is different, someone with central sleep apnea may not snore loudly the way people with obstructive sleep apnea often do, but they may notice more pronounced shortness of breath or wake up gasping for air. Some people have a combination of both, sometimes called complex sleep apnea or mixed sleep apnea, which needs a broader treatment approach that addresses both mechanisms at once; complex sleep apnea usually requires closer follow-up with a specialist.

Severe Sleep Apnea

Healthcare providers gauge severity using the apnea-hypopnea index, or AHI, which counts the average number of respiratory events per hour of sleep. Mild sleep apnea generally falls between 5 and 15 events an hour, moderate sleep apnea between 15 and 30, and severe sleep apnea is diagnosed at 30 or more events an hour.

Severe sleep apnea carries meaningfully higher short-term risks, including sharper drops in blood oxygen levels, a greater chance of heart rhythm problems like atrial fibrillation, and a much higher risk of falling asleep unintentionally during the day, including behind the wheel. If a sleep study points to severe sleep apnea, it’s worth seeing a sleep medicine specialist promptly rather than waiting to see if symptoms improve on their own.

Risk Factors For Sleep Apnea

Some risk factors for sleep apnea are within your control, and some aren’t.

Modifiable risk factors include carrying excess weight, smoking, drinking alcohol in the evening, and sleeping on your back, all of which can make the upper airway more likely to narrow or collapse during sleep.

Nonmodifiable risk factors include getting older, being male, having a naturally narrower airway or larger neck circumference, and a family history of sleep apnea.

In Canada specifically, research using the Canadian Longitudinal Study on Aging found that nearly 1 in 5 adults over the age of 45 is at high risk for obstructive sleep apnea, with men and people with cardiovascular disease, diabetes, or higher body fat showing the highest risk. Men tend to be more prone to sleep apnea than women, particularly before menopause; after menopause, the gap narrows as women’s risk rises. 25% to 30% of men meet criteria for obstructive sleep apnea.

Symptoms And When To See A Healthcare Provider

It helps to separate nighttime symptoms from daytime ones when you’re deciding whether to bring this up with a healthcare provider.

Nighttime symptoms worth mentioning include loud snoring, witnessed pauses in breathing, choking or gasping sounds during sleep, and frequent trips to the bathroom overnight.

Daytime symptoms worth reporting include excessive daytime sleepiness, morning headaches, a dry or sore throat upon waking, trouble concentrating, and mood changes like irritability or low motivation. These other symptoms are easy to attribute to stress or a busy schedule, which is part of why sleep apnea often goes undiagnosed for years.

Contact a healthcare provider urgently if you or a sleeping partner notice breathing stops for long stretches, if you’ve fallen asleep while driving, or if you experience chest pain, an irregular heartbeat, or severe shortness of breath alongside your sleep symptoms.

How Healthcare Providers Diagnose Sleep Apnea

Diagnosis usually starts with a conversation and a screening tool like the STOP-BANG questionnaire, which asks about snoring, tiredness, observed breathing pauses, blood pressure, and a few physical measurements to estimate your risk before any testing begins.

From there, your healthcare provider may recommend an in-lab sleep study, known as polysomnography, which is still considered the gold standard for diagnosing sleep apnea. It tracks your brain waves, breathing, oxygen levels, and movement overnight in a clinical setting, and technicians use those brain wave patterns alongside breathing data to score respiratory events. It’s the most reliable way to confirm obstructive sleep apnea, central sleep apnea, or a mix of both.

For many adults with a straightforward case, home sleep apnea testing is an easier, more affordable alternative. It measures airflow, oxygen levels, and effort to breathe from the comfort of your own bed, though it’s typically reserved for people without other complicating health conditions.

If either test confirms sleep apnea, your provider will usually refer you to a sleep medicine or respirology clinic to discuss treatment options suited to your specific type and severity.

Why Untreated Sleep Apnea Is Worth Taking Seriously

Left untreated, sleep apnea does more than disrupt your rest. The repeated drops in blood oxygen levels put ongoing strain on the cardiovascular system, raising the risk of high blood pressure, heart disease, and congestive heart failure over time. Untreated sleep apnea has also been linked to a higher likelihood of cardiovascular problems more broadly, including atrial fibrillation.

Daytime sleepiness from untreated sleep apnea is also a genuine safety issue, contributing to a higher risk of car accidents and workplace injuries. On the metabolic side, untreated sleep apnea is associated with insulin resistance and metabolic syndrome, and the constant sleep disruption is linked to a higher risk of depression and anxiety.

If you’re heading into a clinical visit, it’s worth jotting down when your symptoms happen, how often, and anything a partner has observed. That record makes it much easier for a healthcare provider to gauge severity and next steps.

Treatment Options Overview

The good news is that sleep apnea is highly treatable, and most healthcare providers start with the least invasive options before considering anything more involved. Broadly, treatment for sleep apnea falls into four categories: lifestyle changes, breathing devices like CPAP, oral appliances, and, in select cases, surgery.

Lifestyle Changes

For many people with mild sleep apnea, lifestyle changes alone can meaningfully reduce symptoms. Losing even a modest amount of weight can decrease the severity of sleep apnea by easing pressure on the airway, since less soft tissue around the neck means less to collapse inward. Sleeping on your side instead of your back keeps relaxed muscles and soft tissues from narrowing the airway, and simple positional aids or a supportive mattress can help you stay there through the night. For people with sleep apnea who mainly experience symptoms on their back, this one change can meaningfully reduce sleep-disordered breathing on its own.

Avoiding alcohol and sedatives in the hours before bed helps keep throat muscles from over-relaxing, and quitting smoking reduces airway inflammation that can make symptoms worse. None of these changes replace medical treatment for moderate or severe sleep apnea, but they’re a reasonable starting point and a useful complement to other therapies for restful sleep.

CPAP And Device-Based Treatments

Continuous positive airway pressure, or CPAP, is the most effective treatment for obstructive sleep apnea and remains the first-line recommendation for moderate sleep apnea and severe cases alike. Among breathing devices, continuous positive airway pressure is the most widely prescribed: the machine delivers a steady stream of pressurized air through a mask, keeping the airway open all night so breathing doesn’t stop. Most people with sleep apnea who try CPAP consistently see a meaningful improvement in daytime energy within the first few weeks.

Mask style matters more than people expect. Nasal masks, full-face masks, and nasal pillows all fit differently, and comparing a few types is often the difference between someone sticking with therapy and giving up on it. If a mask feels uncomfortable, leaks air, or leaves marks, it’s worth asking a provider about a refit rather than assuming CPAP simply isn’t for you. Cleaning the mask and hose regularly, gradually building up nightly wear time, and giving yourself a few weeks to adjust all improve long-term adherence.

Dental Appliances And Oral Devices

A mandibular advancement device is a custom-fitted mouthpiece that gently shifts the lower jaw forward during sleep, which helps keep the upper airway from collapsing. It’s typically used for mild to moderate obstructive sleep apnea or by people who can’t tolerate CPAP. Getting properly fitted by a sleep dentist matters, since an ill-fitting device can cause jaw discomfort without meaningfully helping your breathing.

Surgical Treatment

Surgery is generally reserved for cases where anatomy is the clear obstacle and other treatments haven’t worked. Common surgical treatment options include uvulopalatopharyngoplasty, which removes excess tissue from the throat, and maxillomandibular advancement, which repositions the jaw to create more space for airflow. Candidates are usually selected after a thorough physical exam and imaging to confirm where the blockage is occurring, and recovery can range from a couple of weeks for less invasive procedures to a longer stretch for jaw surgery, so it’s worth discussing realistic downtime with your surgeon beforehand.

Building A Sleep Environment That Supports Treatment

Your mattress and pillow can’t cure sleep apnea, but the right setup makes side sleeping more comfortable, which matters if you’re trying to stay off your back through the night and support the kind of restful sleep your body needs to recover. Look for a mattress with enough contouring at the shoulders and hips to keep your spine aligned on your side, without being so soft that it strains your neck. A pillow with a slightly higher loft under the neck can also help keep your airway open by supporting proper neck alignment.

We cover mattress and pillow recommendations in more depth elsewhere on Best Sleep Society, including comparisons suited to side sleepers and people managing sleep apnea specifically.

• Enough contouring to support side sleeping comfortably
• A pillow height that keeps your neck neutral, not tilted up or down
• Breathable materials if CPAP use makes you run warm overnight
• Enough edge support if you tend to shift positions through the night

Living With Sleep Apnea

Managing sleep apnea day to day is mostly about consistency. Sticking to a regular sleep schedule, keeping your bedroom cool and dark, and avoiding heavy meals or alcohol close to bedtime all support restful, healthy sleep alongside whatever treatment you’re using.

If you’ve been prescribed CPAP or an oral appliance, tracking how often you actually use it, and for how long, gives you and your healthcare provider a clearer picture of whether it’s working. Many CPAP machines log this automatically, but a simple notes app entry works too.

It’s also worth talking openly with a partner or family member about what you’re experiencing. Snoring, restlessness, or a bulky CPAP machine can affect a shared bedroom, and a little communication goes a long way toward making treatment sustainable for everyone involved. If you’re newly diagnosed, connecting with healthcare professionals who specialize in sleep medicine, rather than managing symptoms alone, tends to produce the best long-term results.

Sources: Public Health Agency of Canada Sleep Apnea Rapid Response Survey; Canadian Longitudinal Study on Aging (Thompson et al., Scientific Reports, 2022; Canadian Journal of Public Health, 2024).