Quick Answer: Untreated severe sleep apnea does increase mortality risk, primarily through cardiovascular events. Research shows that 19% of patients with severe obstructive sleep apnea died during follow-up periods, compared to 4% in the non-apnea group. The primary mechanisms are sudden cardiac death (3 to 4 times higher risk, peaking between midnight and 6am), stroke, and heart failure. However, this risk is strongly severity-dependent: mild sleep apnea does not appear to increase mortality. The critical factors are severity (AHI above 30), age over 60, and oxygen saturation dropping below 78% during sleep. CPAP therapy, when used consistently, reduces cardiovascular mortality by roughly 50%. In Canada, an estimated 28% of adults aged 45 to 85 have moderate-to-severe sleep apnea, but only about 6% are diagnosed.
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This is a question people search at 2am after their partner stops breathing for what feels like an eternity, then gasps back to life. It is a question people search after being told they have sleep apnea and wondering how seriously to take it. It deserves a direct, honest answer.
Can Sleep Apnea Actually Kill You?
Yes, but the full answer requires context. Untreated severe obstructive sleep apnea significantly increases the risk of dying from cardiovascular events, primarily heart attack, stroke, and sudden cardiac death during sleep. The risk is real and well-documented in long-term studies.
But "sleep apnea" is not one condition. It ranges from mild (barely noticeable) to severe (dozens of breathing interruptions per hour). Mild sleep apnea does not appear to increase mortality risk in most studies. Severe sleep apnea, left untreated for years, clearly does. The severity, your age, and how much your oxygen levels drop during the night are the three factors that determine where on the risk spectrum you fall.
How Untreated Sleep Apnea Causes Harm
The Repeated Oxygen Drop
Every time you stop breathing during sleep, your blood oxygen level drops. In a single night, a person with severe sleep apnea can experience 30 or more of these drops per hour, hundreds of times per night. Each drop triggers a cascade of stress responses: your heart rate spikes, your blood pressure surges, and inflammatory markers flood your bloodstream.
Over months and years, this nightly assault damages your cardiovascular system in measurable ways:
- Blood vessel damage. Chronic intermittent hypoxia (repeated oxygen drops) damages the lining of blood vessels, accelerating atherosclerosis.
- Persistent high blood pressure. The repeated surges in blood pressure eventually become permanent. An estimated 50% of people with obstructive sleep apnea have hypertension.
- Heart rhythm disturbances. The oxygen drops trigger arrhythmias, abnormal heart rhythms that can, in severe cases, cause the heart to stop.
- Structural heart changes. Over time, the heart muscle remodels in response to the repeated stress, leading to heart failure.
Sudden Cardiac Death During Sleep
This is the most alarming finding in sleep apnea research. A study published in the Journal of the American College of Cardiology found that people with severe sleep apnea have a 3 to 4 times higher risk of sudden cardiac death, and unlike the general population (where sudden cardiac death peaks in the morning), sleep apnea patients face their highest risk between midnight and 6am, precisely when apnea events are most frequent.
The Numbers. In long-term follow-up studies, 42% of deaths among severe sleep apnea patients were cardiovascular or stroke-related, compared to 26% in the general population. A critical threshold is oxygen saturation dropping below 78% during sleep, which increases sudden cardiac death risk by 81%. These are not small numbers. But they apply specifically to severe, untreated disease. If you are treating your sleep apnea, these risks decrease substantially.
Severity Matters: Mild vs. Moderate vs. Severe
Sleep apnea severity is measured by the Apnea-Hypopnea Index (AHI), which counts the number of breathing interruptions per hour of sleep:
- Mild: 5 to 14 events per hour. Not associated with increased mortality in most studies. May cause snoring, mild daytime fatigue, and occasional morning headaches.
- Moderate: 15 to 29 events per hour. Risk elevation is debated. Some studies show association with cardiovascular events; others do not. Worth treating for quality of life and as prevention.
- Severe: 30 or more events per hour. Clear, statistically significant increase in mortality, particularly cardiovascular death and stroke. This is where the data is unambiguous.
Three factors converge to create the highest risk: an AHI above 20, age over 60, and oxygen saturation dropping below 78% during sleep. When all three are present, the risk of sudden cardiac death increases dramatically.
Types of Sleep Apnea and Their Risks
Obstructive Sleep Apnea (OSA)
The most common type, accounting for 80 to 90% of cases. Your airway physically collapses during sleep, usually because gravity pulls the tongue and soft tissues backward. Obesity is the number one modifiable risk factor. OSA responds well to CPAP, weight loss, and positional therapy.
Central Sleep Apnea (CSA)
Much less common (5 to 10% of cases) but more dangerous. In CSA, your brain temporarily stops sending signals to breathe. This is not a mechanical obstruction; it is a neurological event. CSA has a higher mortality rate than OSA, particularly in patients with heart failure. Approximately 20% of CSA patients die within 5 years.
Complex Sleep Apnea
About 6.5% of OSA patients develop central apnea events when they start CPAP therapy. This mixed condition is still being studied, and treatment approaches continue to evolve.
Warning Signs That Sleep Apnea Is Getting Dangerous
If you or your partner notice any of these, take them seriously:
- Gasping or choking awake. Your airway is collapsing severely enough to pull you out of sleep.
- Persistent morning headaches. A sign of chronic overnight oxygen deprivation.
- Extreme daytime sleepiness. Falling asleep during conversations, meetings, or at red lights.
- Microsleeps. Uncontrollable, brief episodes of falling asleep during the day. This is a safety emergency, especially while driving.
- Heart palpitations or irregular heartbeat. The arrhythmias triggered by oxygen drops may be becoming more frequent.
- New or worsening high blood pressure. Often the first clinical sign that sleep apnea is causing cardiovascular damage.
- Your partner reports longer breathing pauses. If the gaps between breaths are growing longer, severity may be increasing.
When to Go to the Emergency Room. Call 911 or go to the ER immediately if you experience chest pain or tightness, sudden severe shortness of breath, sudden weakness or numbness on one side of your body (stroke symptoms), confusion, loss of consciousness, or cold sweats with breathing difficulty. These may indicate a cardiovascular emergency related to sleep apnea.
CPAP: What the Data Actually Shows
Continuous Positive Airway Pressure (CPAP) is the gold standard treatment for moderate-to-severe sleep apnea. Here is what the research says about its effectiveness:
- Mortality reduction: When CPAP users are included in severe OSA studies, the cardiovascular mortality hazard ratio drops from 5.2 to 2.9. That is roughly a 50% reduction in cardiovascular death risk.
- Dose-response: More hours per night on CPAP means better outcomes. Using CPAP for more than 6 hours per night restores normal daytime sleepiness, improves memory, and significantly reduces cardiovascular event risk.
- Even partial use helps: Using CPAP for more than 1 hour per night significantly lowers mortality compared to no use at all.
The Compliance Problem
CPAP works, but compliance is challenging. Depending on how compliance is defined, 30 to 60% of patients do not use their CPAP consistently. Common barriers include mask discomfort, claustrophobia, noise, and the adjustment period (which can take weeks). Despite decades of effort, compliance rates have not improved significantly.
This is not a failure of willpower. CPAP is genuinely difficult to adjust to. If you are struggling, talk to your sleep clinic about mask alternatives, pressure adjustments, or heated humidification options. The difference between using CPAP and not using it is, in severe cases, the difference between a 5.2x and 2.9x cardiovascular risk.
What You Can Do Beyond CPAP
CPAP is the primary treatment for moderate-to-severe sleep apnea. But there are complementary strategies that can reduce apnea severity, particularly for mild cases or while waiting for diagnosis and treatment.
Sleep Position
Back sleeping is the worst position for obstructive sleep apnea. Gravity pulls your tongue and soft palate backward into the airway. Side sleeping keeps the airway more open and can significantly reduce the number of apnea events per hour. For some people with position-dependent sleep apnea, simply switching to side sleeping reduces their AHI dramatically.
Head Elevation
Research published in 2022 found that sleeping with the head elevated at 30 degrees reduced airway collapses and apnea events. Even a modest 7.5-degree elevation (achieved with a wedge pillow or adjustable bed base) improved oxygen saturation and decreased apneic events in mild-to-moderate cases.
Weight Management
Obesity is the number one modifiable risk factor for obstructive sleep apnea. Weight loss reduces the amount of tissue pressing on the airway and can, in some cases, resolve mild sleep apnea entirely. Even a 10% reduction in body weight has been shown to improve apnea severity.
Alcohol and Sedatives
Alcohol relaxes the muscles that keep the airway open, worsening apnea events. The same applies to sedative medications. Avoiding alcohol in the 3 to 4 hours before bed can measurably reduce apnea severity.
Adjustable Beds and Sleep Apnea. An adjustable bed base that elevates the head is one of the most practical complementary tools for sleep apnea management. Research supports head elevation as a way to reduce airway collapse, and an adjustable base lets you find the angle that works best for you without stacking pillows (which tend to shift during the night and can actually worsen neck alignment). We carry several adjustable base options at our Brantford location, and many of our customers with sleep apnea tell us it has made a noticeable difference, both in their apnea symptoms and in their CPAP comfort. An adjustable base does not replace CPAP for moderate-to-severe disease, but it is a meaningful complement.
The Canadian Situation
The Diagnosis Gap
This is the most concerning statistic in Canadian sleep medicine: an estimated 28% of Canadian adults aged 45 to 85 have moderate-to-severe sleep apnea, but only about 6 to 7% of Canadians have been diagnosed. Over 92% of high-risk individuals have no clinical diagnosis. Most people with sleep apnea do not know they have it.
The Wait Time Problem
In Ontario, the median time from referral to actually starting CPAP therapy is roughly 11.6 months: 3.7 months to get into a sleep clinic, 4.75 months from clinic to respirologist, and another 3.1 months from respirologist to CPAP initiation. The Canadian Thoracic Society recommends no more than 4 weeks for severe cases with comorbidities. The reality rarely matches the recommendation.
At-home sleep tests have begun to shorten the diagnostic pathway and are increasingly available in Ontario. If your doctor offers one, it is worth pursuing, as it can bypass months of wait time.
CPAP Coverage in Ontario
Ontario's Assistive Devices Program (ADP) covers up to 75% of the cost of CPAP machines, masks, and supplies for eligible patients with a prescription. This is more generous than most provinces (Quebec, British Columbia, and Alberta offer no universal provincial coverage). But the initial cost ($500 to $2,000 for the machine plus ongoing supply costs) remains a barrier for many families.
For Brantford Residents. If you suspect sleep apnea, start with your family doctor. They can refer you to a sleep clinic or arrange an at-home sleep test. The nearest major sleep assessment program is at St. Joseph's Healthcare in Hamilton. While you wait for diagnosis and treatment (which can take nearly a year in Ontario), optimizing your sleep position, considering head elevation with an adjustable base, and managing weight are all evidence-based steps you can take immediately.
Better Sleep for Better Health
If sleep apnea or snoring is affecting your sleep, an adjustable bed base or a properly supportive mattress can make a real difference alongside your medical treatment. We have been helping Brantford families find honest sleep solutions since 1987.
441 1/2 West Street, Brantford, Ontario
Call 519-770-0001Frequently Asked Questions
Can you die in your sleep from sleep apnea?
It is possible but uncommon. The primary risk is sudden cardiac death during sleep, which occurs at 3 to 4 times the normal rate in people with severe untreated sleep apnea. Research shows this risk peaks between midnight and 6am. However, this applies specifically to severe, untreated cases with significant oxygen desaturation. Mild sleep apnea does not appear to increase mortality risk, and CPAP therapy reduces cardiovascular mortality by roughly 50% when used consistently.
How common is sleep apnea in Canada?
Much more common than most people realize. An estimated 28% of Canadian adults aged 45 to 85 have moderate-to-severe obstructive sleep apnea, but only about 6 to 7% have been diagnosed. Over 92% of high-risk individuals have no clinical diagnosis. Men are at higher risk (roughly 1 in 4 males versus 1 in 20 females), and risk increases with age, particularly after 60.
Does sleeping position affect sleep apnea?
Yes, significantly. Back sleeping (supine position) is the worst for obstructive sleep apnea because gravity pulls the tongue and soft palate backward into the airway. Side sleeping keeps the airway more open and can substantially reduce apnea events. Head elevation (even 7.5 degrees) has been shown in clinical studies to reduce airway collapses and improve oxygen saturation during sleep. An adjustable bed base or wedge pillow can achieve this elevation consistently.
How long does it take to get diagnosed with sleep apnea in Ontario?
In Ontario, the median time from initial referral to starting CPAP therapy is approximately 11.6 months. This includes 3.7 months to reach a sleep clinic, 4.75 months from clinic to respirologist, and 3.1 months from respirologist to CPAP initiation. At-home sleep tests are increasingly available and can significantly shorten this timeline. Ontario's Assistive Devices Program covers up to 75% of CPAP costs for eligible patients.
Can losing weight cure sleep apnea?
In some cases of mild sleep apnea, yes. Obesity is the number one modifiable risk factor for obstructive sleep apnea. Even a 10% reduction in body weight has been shown to improve apnea severity. For mild cases, weight loss combined with positional therapy (side sleeping, head elevation) can sometimes resolve the condition entirely. For moderate-to-severe cases, weight loss is beneficial but usually needs to be combined with CPAP or other medical treatments.