Is sleeping on your left side bad for your heart?

I first saw this theory in the classic horror flick “The Haunting.” A woman purposely sleeps on her left side all the time because it wears out the heart sooner, and she’d just as soon die sooner.

I’ve heard the idea other places too, though. I can’t think of many specific instances, but it’s in the ether of my brain and memory. And some doctor or other once advised me to sleep on my right side because it…drained something better…or something. You see I’m very thorough here.

My positing this question stems purely from personal paranoia. Lately I’ve felt much more comfortable curling up (slightly) onto my left side when falling asleep.

My normally trusty friend Google yields conflicting results. A Yahoo! answers page advises a woman whose baby has a heart ailment not to let her baby sleep on its left side. Some alternative health sources point out extra pressure that can be put on the heart by the right lung, e.g. But an MSN health thread claims: “‘There is no clinical evidence that sleeping in a given position is bad or good for the heart,’ says Dr. Richard Stein, director of preventive cardiology at Beth Israel Hospital in New York City and national spokesman for the American Heart Association. ‘Whatever position is most restful is probably right for the individual.’"

I know, I know…that last one sounds pretty definitive. But my paranoid brain reads “no clinical evidence” as “we just haven’t bothered to run clinical trials or studies about it yet.”

I dunno. Any insights?

I should go to sleep now. And it will probably be on my left side.

It’s not really an answer, but I worked in a pediatric cardiology office and never heard the doctors say anything about that. Also - your heart really isn’t on the left side of your body. It’s in the middle - check out the top diagram on this page, where a Gray’s Anatomy illustration shows it in its proper place, centered. You’ll notice that the heart is tilted such that more of it is on the left portion than the right, but that’s about it.

When you have very specific conditions such as a large intraabdominal mass (near-term pregnancy, say), certain recumbent positions can affect the circulatory system b/c of pressure on large veins returning to the heart.

One could think of unusual cardiac or pulmonary conditions where positions can also affect the function of the heart or lungs.

For a healthy person, it doesn’t matter. Most of us tend to move a fair amount while sleeping anyway.

This was more likely in reference to the esophagus & stomach, and avoiding heartburn. If there’s still a lot of stomach acid & food in your stomach when you go to sleep, it’ll keep it out of the esophagus easier when you sleep on the left (since in almost everyone the entry to the stomach is on the left side). See image here. Studies on people with GERD have shown that this is indeed the case - suffering was reduced when sleeping on the left.

I have always heard that laying on the left side is easier on your heart. Pregnant women are encouraged to sleep on their left sides as it is supposed to be better for mom and baby.
"Although there’s no real harm in sleeping on your right side, lying on your left side is actually good for you and your baby: It improves the flow of blood and nutrients to the placenta and it helps your kidneys efficiently eliminate waste products and fluids from your body. "
"It also makes your heart’s job easier because it keeps the baby’s weight from applying pressure to the large vein (called the inferior vena cava) that carries blood back to the heart from your feet and legs.

Some doctors specifically recommend that pregnant women sleep on the left side. Because your liver is on the right side of your abdomen, lying on your left side helps keep the uterus off that large organ."

I don’t know if it makes a difference if you are not pregnant though, but it seems odd that what is easier on your heart during pregnancy would be harder on it when you are not. When my friend had pre-eclampsia during her pregnancy, she was put on bedrest and had to remain pretty much exclusively on her left side.