Sleep On This Side Of Your Body To Protect Your Heart

Positioning our body for a comfortable night's snooze isn't just important for our sleep health. Doing so can also support our cardiovascular health, particularly if you're someone who is diagnosed with a heart condition.

According to the Heart Failure Society of America, approximately 6.5 million American adults are affected by heart failure. It's reported that the condition is responsible for over 8% of all heart disease deaths across the country. Heart failure occurs when the heart is gradually unable to circulate enough blood throughout the body. While there are two different types of heart failure, both are characterized by lung congestion. Symptoms can become particularly aggravated at night when a person is positioned horizontally in bed, leading to coughing, difficulty breathing, and sleep disturbances.

Researchers from a 2003 study published in the Journal of the American College of Cardiology found that individuals with heart failure tend to avoid sleeping on the left side of their body due to associated discomfort. As a result, experts suggest that patients sleep on their right side instead, but what's the science behind this?

Why heart failure patients avoid left-side sleeping

In the study, researchers examined the sleeping habits of 75 patients with congestive heart failure. Findings revealed a strong avoidance of sleeping on the left side that was not observed in a control group of equal size. 

The researchers theorized that this aversion to left-side sleeping in patients with heart failure may be tied to increased activation of the sympathetic nervous system (our fight-or-flight system) when in this position. Additionally, the researchers also pointed out that patients with heart failure tend to report a heightened awareness of their heartbeat when sleeping on their left side, potentially making sleep more uncomfortable.

Those may not be the only factors affecting the quality of patient sleep, however. More recent research published in 2018 in BioMedical Engineering OnLine has found that when healthy people are lying on the left side of their body, gravity can cause their heart to change position, leading to changes in their electrocardiogram (ECG). This may also be playing a role in the discomfort experienced by people diagnosed with heart failure.

Other ways left-side sleeping affects the heart

Researchers from the study published in BioMedical Engineering OnLine analyzed ECG waves in healthy people while they slept. When they were positioned on their left side, the effects of gravity caused their hearts to rotate in place, producing changes in ECG waves. However, the heart did not alter positioning when patients slept on their right side. So, sleeping on the left side of the body could potentially cause patients with heart failure to have discomfort or problems breathing (via AARP).

In addition to steering clear of left-side sleeping, experts at the Sleep Foundation suggest that heart patients also refrain from snoozing on their back. Doing so can exacerbate symptoms of sleep apnea, a condition that is often seen in patients with heart failure. By sticking to your right side as you dream, you'll likely experience greater comfort and get a healthier night's rest.