MALAYSIANS already have enough to worry about at bedtime – between the heat, mosquitoes and group chats that refuse to go quiet after midnight.
The last thing anyone needs is anxiety about which side of the body to lie on.
Claims that sleeping on the right side is somehow bad for the heart has been circulating for years, passed around with enough conviction to make even the most committed right-side sleeper quietly start reconsidering their life choices.
Is there actually any truth to it?
Verdict:
FALSE
For healthy people, sleeping on the right side poses absolutely no risk to the heart. If anything, the research points in the opposite direction entirely.
The claim appears to have grown out of a misunderstanding of studies looking at sleep positions in people who already had heart disease, not healthy individuals and the conclusions got lost somewhere between the medical journals and the WhatsApp forwards.
Here is what the science says.
The heart sits slightly to the left of centre in the chest and some studies found that sleeping on the left side could cause minor shifts in the heart's position, producing small changes in heart rhythm readings in certain participants.
However, researchers are careful to point out that these changes reflect the heart physically moving around rather than anything going wrong electrically and that nobody was entirely sure whether the variations meant anything clinically significant at all.
A major study published in the Journal of the American College of Cardiology, one of the most respected cardiology journals in the world, tracked 75 patients with congestive heart failure alongside 75 healthy individuals and found something striking – heart failure patients almost universally avoided sleeping on their left side and gravitated strongly towards their right.
The reason was a condition called trepopnea, which is essentially the medical term for the uncomfortable sensation of the heart beating against the chest wall when lying on the left side, which gets worse the more enlarged the heart is.
When those patients rolled onto their right side, the discomfort eased considerably and their breathing improved.
A separate study published in the American Journal of Cardiology found the same pattern:
