Continuous Positive Airway Pressure (CPAP) therapy is the gold standard treatment for obstructive sleep apnea (OSA). While many people understand that CPAP can reduce snoring and daytime sleepiness, fewer realize the serious long-term health consequences of untreated sleep apnea—or of being prescribed CPAP but not using it consistently.

Sleep apnea is not just a nighttime inconvenience. Left untreated, it can affect nearly every system in the body.

What Happens When Sleep Apnea Goes Untreated?

Obstructive sleep apnea causes repeated pauses in breathing during sleep, leading to drops in oxygen levels and frequent micro-awakenings. Even if you don’t remember waking up, your brain and body experience stress throughout the night.

When CPAP is not used, this cycle continues night after night, triggering chronic physiological strain.

Cardiovascular Disease Risk Increases

One of the most well-documented consequences of untreated sleep apnea is cardiovascular disease. Repeated oxygen deprivation and surges in stress hormones raise blood pressure and strain the heart.

Long-term risks include:

• Hypertension that is difficult to control

• Heart attacks

• Heart failure

• Cardiac arrhythmias, including atrial fibrillation

• Increased risk of stroke

Using CPAP consistently has been shown to significantly reduce these risks, especially when started early.

Cognitive Decline and Brain Health

Chronic sleep fragmentation and low oxygen levels negatively affect brain function. Over time, untreated sleep apnea is associated with:

• Memory impairment

• Reduced attention and concentration

• Slower processing speed

• Executive dysfunction

There is also growing evidence linking untreated sleep apnea to an increased risk of mild cognitive impairment and dementia, particularly in older adults.

Mood Disorders and Mental Health

Sleep apnea disrupts emotional regulation. People who do not use CPAP are at higher risk for:

• Depression

• Anxiety

• Irritability and mood instability

• Decreased stress tolerance

Because fatigue and low mood can reinforce each other, untreated sleep apnea often creates a cycle where mental health worsens alongside sleep quality.

Metabolic and Endocrine Effects

Untreated sleep apnea interferes with glucose metabolism and hormone regulation. Long-term consequences may include:

• Insulin resistance

• Type 2 diabetes

• Weight gain and difficulty losing weight

• Increased appetite and cravings

Poor sleep also disrupts hormones that regulate hunger and satiety, making lifestyle changes more challenging.

Daytime Functioning and Safety Risks

Without CPAP, excessive daytime sleepiness often persists. This increases the risk of:

• Motor vehicle accidents

• Workplace injuries

• Errors in judgment and decision-making

Over time, chronic fatigue can affect job performance, relationships, and overall quality of life.

Impact on Relationships and Quality of Life

Untreated sleep apnea affects more than just the individual. Loud snoring, gasping, and restless sleep can disrupt a partner’s rest, leading to relationship strain. Fatigue, irritability, and withdrawal can further erode emotional connection and social engagement.

Many people don’t realize how much sleep apnea has limited their lives until effective treatment begins.

Why CPAP Adherence Matters

CPAP only works when it’s used consistently. Skipping nights—or abandoning therapy altogether—allows the harmful effects of sleep apnea to continue. While adjustment can be challenging, mask fit issues, dryness, pressure discomfort, and anxiety can usually be addressed with proper support.

CPAP is not a sign of weakness—it’s a tool that protects long-term health.

Final Thoughts

Not using CPAP doesn’t just mean poorer sleep—it can mean years of accumulated damage to the heart, brain, metabolism, and mental health. The long-term consequences of untreated sleep apnea are serious, but they are also largely preventable.

Using CPAP consistently is an investment in longevity, cognitive health, emotional well-being, and overall quality of life. If CPAP feels difficult, the solution is rarely to give up—it’s to seek help and optimize the therapy.

If you or someone you know struggles with sleep, please click the orange button below to take a free online sleep test and talk with one of our sleep health professionals.