Dr. Day is a cardiologist/electrophysiologist at the Intermountain Medical Center Heart Institute in Salt Lake City, Utah. He graduated from Johns Hopkins Medical School and completed his residency and fellowships in cardiology and electrophysiology at Stanford University. He is the former president of the Heart Rhythm Society and currently serves as the president of the Utah chapter of the American College of Cardiology.
Is Left or Right Side Sleeping Best for Your Heart?
Most of my cardiac patients sleep better on their right side. Is right side sleeping best for your heart? In this article, I discuss the science of behind right versus left side sleeping.
Gravity and Left vs. Right Side Sleeping?
Gravity plays a role in where the heart goes during sleep. For example, if you sleep on your left side, then gravity will pull your heart toward your chest wall. In contrast, gravity pulls the heart toward the center of the chest with right side sleepers. This subtle change in where gravity pulls your heart may affect symptoms, cardiac output, or even your heart rate.
Why Back Sleeping is Probably Bad for the Heart
If you are carrying any extra weight, back sleeping is definitely bad for your heart. This is because when you sleep on your back, the extra weight collapses your airway (sleep apnea). And studies show that sleep apnea dramatically increases your risk of heart failure and atrial fibrillation.
Stomach sleeping is another possibility. However, as I have learned personally, stomach sleeping is a perfect recipe for neck and back issues.
4 Reasons to Sleep on Your Right Side
If you suffer from heart issues, talk with your doctor about whether you should sleep on your right or left side. Based on the science, here are four reasons why you may want to consider sleeping on the right.
1. Less Shortness of Breath
As far back as 1937 doctors have noted that heart patients breath better sleeping on their right side. Indeed, the worse the cardiac function, the more likely people are to sleep right side down. While the reason for this isn’t entirely clear, it may have to do with a better venous return and lower pressures within the heart and lungs.
2. Better Cardiac Output
For the same reasons as number one above, cardiac output may be better with right side sleeping. Once again, gravity pulling the heart toward the center of the chest may optimize cardiac performance.
3. Fewer Palpitations
No one likes the sensation that their heart isn’t beating correctly. As the heart is in the center of your chest with right-sided sleeping, studies show that palpitations become much less noticeable. In contrast, when you are on your left side, the heart is pulled to the chest wall, and you may feel every irregular beat of your heart.
While many atrial fibrillation patients have noted that they have fewer arrhythmias when sleeping on the right side, I could find no studies supporting this finding. Thus, when it comes to sleeping and arrhythmias, I suggest sleeping in whatever position that seems to help.
4. Lower Heart Rate and Less Sympathetic Nervous Activity
The sympathetic nervous system is the fight or flight response. This fight or flight response makes the heart rate and blood pressure go up.
For most of my patients, sympathetic nervous system stimulation makes their heart failure, chest pain, or arrhythmias worse. And when it comes to sleeping and sympathetic stimulation, studies show that right-sided sleeping may be better.
3 Reasons to Sleep on Your Left Side
Not everyone does best with right side sleeping. In fact, there are three distinct groups of people that may do worse.
1. Acid Reflux Sufferers
People suffering from acid reflux may sleep better on their left side. This is because studies show that acid reflux may be worse with right side sleeping. Thus, if your acid reflux is causing you more symptoms than your heart, you may want to consider sleeping on your left side.
2. Vagus Nerve Arrhythmias
The vagus nerve connects the heart, brain, and gut. Because of this connection, vagus nerve activation may be an important cause of arrhythmias.
With vagus nerve stimulation, you get increased parasympathetic activity which is the exact opposite of the fight or flight response with sympathetic stimulation. Thus, to quiet your vagus nerve at night, studies suggest that you may want to try sleeping on your left side.
3. Too Slow of a Heart Rate at Night (Bradycardia)
If you have ever worn a heart monitor, your doctor may have told you that your heart beats too slow at night. If this is the case, sleeping on your left side could stimulate a sympathetic response and increase your heart rate.
Does it Really Matter Which Side You Sleep On?
For those of you who suffer from sleep issues, you may be asking does it matter which side is down? I know for myself that I feel incredibly grateful for a great night of sleep regardless of which side is down. Indeed, trying to force sleep on my right or left side would only intensify my insomnia.
Thus, I can’t definitively answer the question, is left or right side sleeping best for your heart. The answer is a personal choice based on your specific situation and what feels best for you.
Do you prefer sleeping on the right or left side? Please leave your thoughts and questions below. For questions, please be patient as it may take me a few weeks to post a response.
Want to read more about sleep optimization? Please check out this article I wrote called 10 Ways to Cure Insomnia without Medications.
Disclaimer Policy: This website is intended to give general information and does not provide medical advice. This website does not create a doctor-patient relationship between you and Dr. John Day. If you have a medical problem, immediately contact your healthcare provider. Information on this website is not intended to diagnose or treat any condition. Dr. John Day is not responsible for any losses, damages or claims that may result from your medical decisions.