Sleeping posture is how you place your body when you are asleep. There are three main sleeping postures which are sleeping on your back, sleeping on your stomach, or sleeping on your side.
What are the most common sleeping postures?
Most people sleep on their sides. According to a recent study, 54% of time spent in bed is in the side position, 38% is spent on the back, and 7% is spent on the stomach.
However there are different positions for each major type. For example, back sleepers can sleep with the arms and legs straight or they can sleep with the arms and legs outstretched. Side sleepers can sleep in the fetal position or slightly curved.
How does sleeping posture affect sleep and health?
The main way that sleeping posture affects sleep and health is simply through the physical mechanics of the sleeping posture. There are no inherently better sleeping postures that will enable you to achieve deeper sleep. There are three main ways that sleeping posture can affect sleep and health.
First, sleeping posture can affect sleep through spine and joint alignment. For example, sleeping on your stomach will force you to twist your neck in order to be able to lay your head down. Sleeping on your sides may add pressure to your shoulders. Generally, if you find that one sleeping posture causes physical pain, it may be time to try another sleeping posture.
Second, sleeping posture can affect sleep through changing how you breathe. For example, sleeping on your back may increase snoring and sleep apnea, which will interrupt sleep.
Third, sleep posture can affect reflux, which is when stomach acid begins to affect the esophagus. Sleeping on your side may reduce the experience of reflux.
How does sleep posture affect the brain?
A recent study had people sleep on the backs or sides while in an MRI machine and with an EEG. Surprisingly they found differences in brain activity between the sleeping postures. While these results are a little hard to understand, this paper does show that sleeping posture can affect brain activity.
How does sleeping posture affect dreaming?
How sleeping posture affects dreams is a much less frequently asked question than how sleeping posture affects sleep or health. Still there have been a few studies that have asked this question.
Left side sleepers might have more nightmares
In a study published in 2004, Agargun found that the rates of nightmares were significantly higher for left side sleeps versus right side sleeps. A total of 63 people were included in this study. 15% of those that slept on their right side suffered from nightmares, while 40% that slept on their left side suffered from nightmares.
This finding, however, should be taken with care. There were very few other differences in dream content between the different sleep positions. Additionally, left side sleepers had better sleep in general, which is a finding that is additionally surprising.
Stomach sleeping might have more intense dreams
In another study conducted in 2012, researcher Yu conducted a large survey with 670 people and asked about general dream behavior and sleeping posture. Sleeping in the prone posture was associated with paranoia, delusion, grandiosity, persecution, erotomania, sex, fighting among other things.
However only 5% of the people (25 people) in this survey slept in the prone. Because of the relatively few people, the results may not fully reflect how posture affects dreams.
Stomach sleep might result in anger
A study conducted in 2018 conducted a survey of 729 university students. Those that slept on their stomach reported the highest levels of anger and feelings of anger. While not specifically related to dreams this study can potentially show a link between emotional or mental experience and sleep posture.
Back sleeping is associated with sleep paralysis
Sleep paralysis is when a person wakes up, but is unable to move. This happens because of an incomplete awakening from sleep. The body is paralyzed during REM sleep (so we don’t act out our dreams). Sleep paralysis happens more frequently when people sleep on their backs.
Interestingly, sleep paralysis and lucid dreaming are correlated phenomena. This means that people who have more lucid dreams are more likely to experience sleep paralysis. So it is possible that back sleeping might result in more lucid dreams as well, though this has not yet been investigated.
There’s definitely evidence to show that sleep posture can affect dreams, mood, and brain activity during sleep. There are specific and isolated studies that point to specific differences in dream content. However, most of these studies involve surveys and do not yet paint a consistent picture.
Therefore, it is likely that sleeping posture can affect our dreams. It is not yet known how sleeping posture affects our dreams.