How Does Sleep Apnea Affect the Heart?

3 min read

Last updated: February 2024

People who have sleep apnea pause in their breathing while asleep. These pauses occur anywhere from 5 to 30 times an hour and last from a few seconds to up to a minute or longer. Snoring is often involved.^1,2

These pauses in breathing affect sleep quality and can lead to fatigue and drowsy driving. Research also shows that untreated sleep apnea leads to serious health problems, especially cardiovascular disease (CVD), obesity, stroke, and type 2 diabetes.^1,3

Diseases related to sleep apnea

Researchers are still learning about the effects that sleep apnea can have on your health, but they have noticed some trends. Multiple studies have shown that sleep apnea increases the risk of CVD and high blood pressure. It also increases your risk of death due to cardiac arrest. Those living with both sleep apnea and pre-existing conditions, like heart failure, are at a higher risk of death than those living with heart failure alone.⁴

Sleep apnea causes high blood pressure. High blood pressure caused by sleep apnea can lead to abnormal heart rhythms (arrhythmias). The heart has 4 chambers, and they must pump in a particular way to send blood through the lungs and then out into the body. Arrythmias mean that the heart is not working as it should. Less blood may move through the body so some cells may not get the oxygen they need. Arrhythmias can result in heart attacks, heart failure, or strokes.⁴

Sleep apnea is also associated with obesity, stroke, and type 2 diabetes. These disorders can also increase the risk of CVD.^1,3,4

How does sleep apnea increase your risk of heart disease?

Normally during sleep, your blood pressure and heart rate slow down and speed up at different times throughout the night. However, in sleep apnea, these cycles are thrown off.⁵

When you have a pause in breathing while sleeping, the body has an instinctual startle response. This wakes you up just enough to start breathing again. During each of these startle responses, your blood pressure and heart rate rise. This is another reflex to move more oxygen and blood throughout the body. Even with the reflexive rise in blood pressure, your body takes in less oxygen because of these pauses. This decrease in oxygen increases your risk of other diseases. Also, these spikes in blood pressure may last long after the pause in breathing. This is what is believed to cause high blood pressure.^1,2,4,5

Sleep apnea has dramatic effects on heart rate. A drop in oxygen activates the sympathetic nervous system, sending a ‘fight or flight’ message to the body. This response increases heart rate during pauses in breathing but also may increase heart rate while awake. The drop in oxygen can also cause the opposite effect, slowing the heart rate dangerously. This may lead to cardiac arrest and death.^4,5

Low oxygen stresses the body, causing it to send "danger" signals. These danger signals can trigger many other effects like inflammation and insulin resistance. Insulin resistance increases the risk of type 2 diabetes. Insulin resistance can also lead to obesity, another risk factor for CVD.^1,4,5

What should I do next?

The most recognizable symptom of sleep apnea is experiencing audible pauses in breathing during the night. Other symptoms may include heavy snoring, excessive sleepiness, poor concentration, or trouble staying asleep.^1,2

Researchers estimate that up to 85 percent of people living with sleep apnea have not been diagnosed. If you think you may have sleep apnea or are snoring, talk to your doctor.⁵

If you have been diagnosed with sleep apnea, follow your doctor’s instructions on how to use your CPAP machine. Scientists believe that using the CPAP machine allows the body to recover and heal the damage caused by sleep apnea.^2,4,5

However, it may take time to see the benefits of the CPAP because the body needs time to repair what could be years of damage. Treating sleep apnea as early as possible can prevent this damage before it leads to more serious diseases.^2,4,5

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markb Member
I first learned of my sleep apnea after my first visit to cardiologist who was treating me for Atrial fibrillation which was discovered by my primary physician. I had not been taking care of myself, was traveling for work nine months straight, coming home Fri nights, leaving Mon mornings. I was not sleeping well being gone, Waking frequently, bathroom trips 5-8 times a night and getting only couple hours sleep each nite, that along with stress from project I was working, did me in! I ended up with afib and a blood clot in my heart. This all lead to heart failure and was in hospital for two weeks! My cardiologist saved my life with appt with sleep Dr and finally Cpap machine! It has been night and day with the cpap, I now sleep all nite, feel rested, and I have not had any afib events since on the cpap! For me it has been a miracle and lifesaver! I now promote cpap sleep therapy to anyone I see may need it!
1. Kristin Schwoebel Community Admin
 Thank you for sharing your experience Mark, sounds like you have had quite the journey. So happy to hear you are feeling better with your CPAP and you have had such a positive experience. We appreciate you being part of our community! Warmly, Kristin (SleepApnea.Sleep-Disorders.net Team Member)
danitaa Member
I have A-Fib. Every time it goes off the rails, my cardiologist asks me about sleep. I have insomnia and she says it's a connection between the two. I'm more watchful of my sleep patterns, if you can call them that and I have changed two things. I don't go out after a sleepless night and I do take an afternoon nap. It has gotten better. No more five day hospital stays.
1. Matthew-Ferry Community Admin
 <inline-mention user-id="4115324" username="danitaa"/> , we're so glad to hear you've learned what works for you! And that you've managed to have less extensive hospital visits. It's critical to know your limits to combat exhaustion and flares. Thank you for sharing with the community. Be well, Matt (Team Member)