What’s the Best Sleep Position?

I get asked the sleep position question with some frequency in my practice and my answer has typically been along the lines of whatever position is most comfortable, other than on your stomach.

Stomach sleeping tends to be problematic from a musculoskeletal standpoint because, unless you happen to sleep on a chiropractic or massage table (with a slot or opening for your nose and mouth) that allows you to breathe with your face straight down), you’ll always need to have your head turned to one side or the other. Hours of having your head stuck in rotation tends to cause some neck issues, as you might imagine. There’s also potential for decreased air flow into the lungs, leading to reduced oxygenation and symptoms like chronic fatigue.

Now that we have dispatched stomach sleeping as the worst sleep position, we’re left with variations of side sleeping and back sleeping. Now things get more complicated, because the theoretically best position varies depending on what aspects of health we’re looking at.

From a musculoskeletal standpoint, assuming that you’re sleeping on a supportive bed and have a pillow that’s of appropriate thickness and firmness for your neck, back sleeping is probably best. While on your back, the various joints and muscles are in a well-aligned and relaxed position.

Particularly when it comes to the shoulder joints, back sleeping is generally much more comfortable and less likely to cause problems with the shoulders than side sleeping. Although how much better back sleeping is for the shoulders than side sleeping really has not been firmly established. One research study found that approximately 90% of people with non-traumatic shoulder complaints were side sleepers. The thing is, side sleeping is the most common sleep position, with about 70% of people sleeping on their sides at least half the time, and there’s a lot of side sleepers who don’t have shoulder problems.

From my observations over the years, it seems like side sleeping does exacerbate existing shoulder issues and injuries and may delay recovery from them, but I have some doubts that side sleeping in and of itself initiates shoulder problems in most cases.

As with back sleeping, having appropriate support from one’s bed and pillow will reduce potential problems caused by side sleeping.

Aside from potentially causing irritation of shoulder problems, there are some advantages of side sleeping compared to back sleeping.

One relatively well-known benefit is that side sleepers tend to snore less and have fewer issues with sleep apnea than back sleepers.

Recently, I came across an interesting study on the effects of sleep position on the function of the glymphatic system. That’s not a typo. The glymphatic system is the brain’s version of the lymphatic system that uses cerebrospinal fluid to carry away waste products from the brain tissues.

A build up of one particular brain waste product, beta-amyloid, is associated with the development of dementia, particularly Alzheimer’s disease. While there may be several factors in the build up of beta amyloid in Alzheimer’s, one potential issue is decreased clearance of it by the glymphatic system, and one of the things necessary for optimal gymphatic system function is sleep.

But not just any sleep. Recent research has shown that sleep position makes a significant difference in glymphatic system function. It seems that it works best when sleeping on your side, and more specifically, sleeping on your right side. So, ranking sleep positions for glymphatic system function, sleeping on the right side is best, the left side is still pretty good, then back sleeping is a distant third and stomach sleeping isn’t even in the running.

Ultimately, adequate (7 hours or more per night) good quality sleep was found to be one of the best things for healthy glymphatic function, but right side sleeping did give things a boost.

So, going back to the original question of what’s the best sleep position, my opinion is whatever position (other than stomach sleeping or some weird contorted position with arms and legs going every which way) that allows you to sleep most comfortably and get the most quality sleep.

Other than that, if you do not have any shoulder problems, side sleeping with a pillow that supports your head in a relatively well-aligned position (so that the neck is at least close to straight with the rest of the spine) is probably the best overall position, with an advantage going to sleeping on the right side versus the left.

If you have shoulder pain or other musculoskeletal issues that prevent comfortably side sleeping, then sleeping on the back (again, assuming a supportive bed and pillow) is probably better and will likely allow for better quality sleep.

It really all comes down to what position you sleep best in, although if you’re a stomach sleeper, it might be worth trying to retrain yourself to sleep in a different position in the long run.

Until next time…

George F. Best, D.C.