Sleeping on Left Side vs Right Side: What’s the Best for You?
Everyone sleeps, but you may not be getting all the health benefits it offers. Many factors affect the depth and success of your sleep cycle—the food you eat, how much time you’ve spent outside, your exercise routine, and your sleeping position. No matter if you sleep on your left or right side, stomach, or back—there’s a lot of info out there about the best sleeping position. We’ll cover why sleeping position matters, especially when it comes to your heart health.
Sleep Position Matters
The best sleep position for you does more than help you get comfortable; it can lead to or prevent certain sleep disorders. Stomach sleepers, for example, are more prone to lower back pain and shoulder pain due to the increased pressure on their lower spine. If you currently deal with lower back pain and you sleep on your stomach, look for a firmer mattress that prevents the pelvis from sinking into the mattress’s surface. We typically don’t recommend stomach-sleeping at all because of the pain risk it carries.
Back sleeping, on the other hand, is the position that most readily keeps the spine in a neutral position and prevents neck pain. A neutral spine is relatively straight and level from the top of the head down to the pelvis. A neutral spine, no matter the sleeping position, should always be your goal.
The neutrality of back sleeping can change based on your weight and mattress type. For example, if you have a mattress that’s too firm for your body weight, the mattress may not conform to the shoulders and hips. That can put pressure on the spine and force it out of alignment rather than supporting the curves of the upper and lower back.
As good as back sleeping is for spinal alignment, it isn’t the best position for every medical condition. For example, gastroesophageal reflux disease (GERD) can be worse when back sleeping. In this position, gravity doesn’t keep stomach acid in the stomach. Additionally, nighttime acid reflux can do more damage to the esophagus because there’s less saliva production and swallowing, which limit acid in the esophagus during the day.
The sleeping position that’s best for you depends on a combination of your medical conditions and your personal preferences. You can keep your spine neutral in almost any position as long as you have the best mattress for your sleep style.
We’ve already mentioned how firmer mattresses can help stomach sleepers, but side sleepers have unique needs too. Back sleepers generally enjoy the most mattress options because of their naturally neutral spinal position. For them, personal preference gets to play a bigger role.
We’ve spent a lot of time on stomach and back sleeping, but what about side sleeping? As the most common sleep position and the healthiest for the heart, it deserves special attention.
The Benefits of Side Sleeping
When it comes to the heart, side sleeping wins out because it decreases the risk of acid reflux, snoring, and it’s best for the heart. Side sleeping is the most common sleeping position among humans and animals. This one position has three basic variations:
- Fetal Position: As the name suggests, this position mimics the position of a fetus— the knees tucked towards the chest with the hands pulled in. The slight curve of the spine in this position relieves pressure and stress on the back.
- Yearner Position: The yearner sleepers on one side with the legs straight and arms extended straight forward as though reaching for someone.
- Log Position: The log sleeper lies on their side with legs relatively straight and arms straight at the sides.
While these are the most common side positions, many people are combo sleepers who switch to a different side or even back or stomach position during the night. The best mattress for side sleepers cushions and supports the curves of the body evenly. They need pressure relief at the shoulders and hips with plenty of support for the head and feet.
Side sleeping has some interesting health benefits. During the day, your brain creates waste proteins. These proteins build up and clog the tiny interstitial spaces in the brain. While you sleep, the glymphatic system removes these toxic proteins. The cleansing process causes brain cells to shrink, which opens those tiny spaces so spinal fluid can flush through. This system works 24 hours a day, but it’s 90 percent more active while you’re asleep.
A 2015 study found that side sleeping increases the efficiency and activity of the glymphatic system. Researchers used MRI images to view what happens in different sleep positions. And, of the main three positions, the side sleeping had the greatest impact on brain cleansing. Scientists believe that a slow down in this cleansing process could contribute to Alzheimer’s disease. Therefore, a sleeping position that allows this process to work freely is best for brain health.
Your sleeping position can lead to sleeping disorders, as well. Sleep apnea, more specifically obstructive sleep apnea, is a sleeping disorder in which breathing periodically stops throughout the night. People with this condition stop breathing hundreds of times during their sleep cycle, which causes a drop in oxygen levels. These breathing episodes also cause them to briefly wake up over and over again during the night. If you have sleep apnea, you may be in bed for a full seven hours, but still wake up exhausted.
Heavy snoring is a common symptom of sleep apnea, and side sleeping can help. It improves oxygen levels because it reduces the breathing episodes related to sleep apnea. In a study conducted amongst overweight sleepers, it was found that side sleeping improved oxygen levels by six to seven percent. The benefits went down the heavier the sleeper, but it still made a significant difference in their sleep health.
Side Sleeping for a Healthier Heart
Side sleeping creates the right conditions for optimal heart health too, but both sides aren’t equal. Sleeping on the left side isn’t necessarily bad for your health, it’s just not as healthy as sleeping on the right side.
Lying on the right side creates more space in the chest cavity and reduces pressure on the heart muscles. Imagine the chest cavity with the heart on the left side. If you lie on your right side, gravity pulls the heart into the chest cavity rather than against the wall of the rib cage. That puts less pressure on it and reduces its nighttime workload. If you’re already suffering from a heart condition like heart disease, that extra work can take its toll.
The question of heart health was at the center of a 2016 study among patients with congestive heart failure (CHF). Researchers noticed that people with CHF consistently reported discomfort when they slept on their left sides. They consciously chose their right sides over the left side to reduce their discomfort. The same pattern was not observed in a control group in which there were no patients with CHF. More importantly, those who avoided sleeping on the left side had improved heart test results at the end of the study.
Right-side sleeping has also been shown to benefit the sympathetic nervous system. That’s the part of your nervous system that controls your fight or flight response. That also means it influences your heart rate and blood pressure. The pressure relief of right-side sleeping regulates blood flow, which stabilizes the heart rate and blood pressure. Whether you’re suffering from a heart condition or not, a stable heart rate and blood pressure can help you sleep and improve overall health.
Making the Change to the Right Side
If sleeping on your side isn’t your preferred sleeping position, take heart. As children, we spend almost equal time among the three sleeping positions. By the teen years, the side position starts to take the lead. By age 45, most people prefer the side over any other common sleep position.
You can train your body to sleep differently. Bolsters and pillows are the easiest way to make the change. Regular or body pillows tucked behind your back can help keep you on the right side. You can also try sleeping on a couch or in a day bed, where a backrest supports the back and keeps you in the right position. Keep in mind that your position preferences can change over time. You may need to revisit your training after a few months or years.
As you age, the benefits of right-side sleeping increase. Aches, shoulder pain, and medical conditions have a bigger influence on your nighttime comfort. Age reduces the number of times you switch positions. Therefore, you’re more likely to end in the position in which you started. That’s a good thing for your heart health.
We do want to mention the exception to right-side sleeping, and that is pregnant women. In these cases, sleeping on the left side increases blood flow to the fetus. Obviously, stomach sleeping is out, and back sleeping can put too much pressure on the spine. For pregnant women, sleeping on the left side is the healthiest option.
A Final Word
If you’re at risk for heart issues, sleeping on the right side could have long-term benefits. If you’re older, you may already find yourself gravitating to the right— but when you make a conscious choice, choose the right side. Make sure you’ve got a mattress that supports your sleeping position—one that conforms and cushions your shoulders and hips, will keep the spine aligned, and maintain comfort all night long. If you can start the night out right, your heart with thank you.