Having sleep apnea increases your risk of developing cardiovascular (heart and blood vessel) conditions. These can include heart failure (when the heart doesn’t pump blood as efficiently), coronary artery disease (a buildup of plaque in the arteries that supply blood to the heart), and related complications.

Understanding how sleep apnea and its treatment can affect the heart can help you improve your quality of life. Keep reading to learn about the possible links between sleep apnea and heart failure.

How Sleep Apnea Affects Heart Health

People with sleep apnea experience episodes in which they stop breathing for 10 seconds or longer during sleep. These pauses can lower oxygen levels in the blood and put strain on the heart.

Because of how sleep apnea affects the heart, it’s a risk factor for developing heart failure. In heart failure, the heart is unable to effectively pump blood due to weakness or stiffness. Between 20 percent and 60 percent of people with heart failure are estimated to have obstructive sleep apnea (OSA).

Most people with sleep apnea have one of two primary types: OSA or central sleep apnea (CSA).

• OSA — Soft tissues in the upper airway relax too much, causing the throat to collapse and prevent airflow to the lungs.
• CSA — The brain doesn’t effectively communicate with the muscles in charge of breathing.

Common symptoms of sleep apnea include loud snoring, choking or gasping for air, and daytime fatigue (tiredness that doesn’t improve with rest). Both types of sleep apnea cause breathing to start and stop abruptly during sleep, which can strain the heart.

Sleep Apnea’s Effect on the Heart

If your breathing stops while you’re sleeping, your blood oxygen levels fall. This drop prompts your body to make and release adrenaline — also called epinephrine. This is the hormone often referred to as the stress hormone.

If your breathing patterns are interrupted often, your levels of adrenaline can stay high. When levels remain high, it can cause hypertension (high blood pressure). This can lead to inflammation that damages blood vessels over time.

Low blood oxygen levels due to OSA can also affect the heart’s electrical rhythm. Because of this, OSA can cause you to develop cardiac arrhythmias (irregular heartbeats), such as atrial fibrillation, if your body stays in stress mode too long.

Poor sleep quality and high blood pressure can also contribute to coronary artery disease. This heart condition is often caused by plaque buildup within the arteries — what doctors call atherosclerosis.

Plaque is made up of cholesterol, fat, and other substances. When plaque forms in the coronary arteries, it can cause them to narrow, limiting blood flow to the heart.

Untreated Sleep Apnea and Heart Failure Risk

Sleep apnea affects the cardiovascular system in a variety of ways, all of which can influence heart failure risk.

Low blood oxygen levels can lead to high blood pressure, which forces the heart to exert more effort to pump blood. This added strain raises your risk of developing heart failure.

When sleep apnea causes arrhythmias, these abnormal heartbeat patterns can weaken your heart over time, leading to heart failure. Meanwhile, reduced blood flow from coronary artery disease can also strain the heart, raising heart failure risk.

Compared to people without sleep apnea, those living with untreated sleep apnea have double the risk of having a heart attack.

Types of Heart Failure

There are different types of heart failure. OSA is more likely to be found in people with heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF).

Both HFpEF and HFrEF are types of left-sided heart failure. Ejection fraction (EF) — a measure of the blood that’s ejected (pumped out) of the heart — can either be preserved (normal) or reduced. Some research points to HFpEF being the more common type of heart failure in people with OSA.

Diastolic Heart Failure

In HFpEF — or diastolic heart failure — the left ventricle (lower left chamber) is unable to relax and fill with blood properly. This means that even though the heart is capable of pumping normally, there isn’t enough room in the left ventricle to store that amount of blood.

HFpEF is usually due to areas of the heart becoming thicker or stiffer, which causes the left ventricle to shrink. Having high blood pressure or coronary artery disease can increase your risk of developing HFpEF.

Systolic Heart Failure

In HFrEF — or systolic heart failure — the left ventricle isn’t able to contract strongly enough to pump blood out. HFrEF is often caused by health conditions that weaken the heart over time, which lead to weaker contractions that are less effective for pumping blood.

One small study looked at people with overweight and CSA or OSA. The study found that people with CSA had lower ventricular EF (weaker left ventricle pumping) compared to those with OSA. The study authors also noted that people with CSA went to the hospital more often for heart failure and had a higher risk of death than those with OSA.

How Sleep Apnea Treatment Impacts Heart Failure Risk

The good news is that treating your sleep apnea may help reduce your risk of developing heart failure. This is because effective treatment of sleep apnea can help to calm the body’s stress signals, reduce blood pressure, and promote stable heart rhythms.

Sleep apnea treatment options, such as continuous positive airway pressure (CPAP) machines, can help you breathe better while sleeping. This can help reduce the risk of heart failure in people with sleep apnea.

CPAP Use and Heart Health

A large Danish study found that use of a CPAP machine significantly lowered heart failure risk, especially among older adults. Those over 60 years old with sleep apnea who didn’t use a CPAP machine were 38 percent more likely to develop heart failure than people the same age who were treated with CPAP.

A 2025 study looked at CPAP use by people with sleep apnea and cardiovascular disease. The study authors found that CPAP use lowered the risk of cardiovascular events like stroke and heart attack by 17 percent.

This risk reduction was specific to people whose sleep apnea caused big drops in blood oxygen levels or spikes in heart rate. The risk of these events was reduced even more for people using CPAP who didn’t have a lot of daytime sleepiness or high blood pressure.

However, the study authors noted that CPAP use didn’t appear to make a big difference for everyone, which may have to do with large portions of people not using their CPAP machines enough to see benefits.

Other Sleep Apnea Treatments and Heart Health

Less research is available on the effect of oral appliances, such as mandibular (jaw) advancement devices, on cardiovascular health.

One study found that use of these oral devices was about as effective as CPAP therapy at reducing life-threatening cardiovascular events in people with severe OSA. Many studies show that it may be less effective at reducing the risks of cardiovascular diseases due to OSA, but the loss in effectiveness may be made up by the fact that people wear these devices more frequently.

Signs of Heart Failure

Signs of heart failure can develop suddenly or slowly over time. If your heart isn’t working well, you may notice signs of heart failure, including:

• Difficulty catching your breath
• Wheezing while breathing
• Persistent coughing that produces mucus
• Trouble exercising as much as usual
• Unusual weakness or fatigue
• Swelling in the lower body or belly
• Heartbeats that feel fast or otherwise irregular, such as fluttering
• Chest pain
• Fast weight gain
• Loss of appetite
• Nausea
• Decreased alertness
• Difficulty focusing

Some heart failure symptoms can also be symptoms of sleep apnea. Fatigue, decreased alertness, trouble focusing, and shortness of breath can be caused by either health condition.

When To Seek Urgent Medical Care

Certain symptoms can be signs of a life-threatening emergency. Go to the emergency room or call 911 if you:

• All of a sudden can’t catch your breath and are coughing up mucus that looks pink, white, or foamy
• Feel like you can’t catch your breath and also have chest pain, irregular heartbeat patterns, or pass out
• Have pain in your chest
• Feel very weak
• Faint

Heart failure can lead to these symptoms, but so can other causes. It’s important to get evaluated to find out whether heart failure is the root cause so you can receive the right treatment.

When To See Your Doctor

Just like sleep apnea can lead to heart failure, having cardiovascular conditions can worsen symptoms of sleep apnea. See your healthcare provider if you experience:

• Any symptoms of heart failure
• Worsening sleep apnea symptoms
• New or worsening heart failure symptoms
• Five-pound weight gain or more within three days while being treated for heart failure

Check in with your cardiologist as soon as possible if you notice symptom changes during heart failure treatment. New or more severe symptoms of heart failure that occur during treatment can mean that your current treatment plan isn’t helping. Work with your doctor to find the best ways to balance your heart and sleep health.

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