I have been presented with the following conundrum. Either you sleep on your back and snore, or sleep on your right side and get acid reflux, or sleep on your left side and put a heavier load on your heart, thus weakening it.

I d not have or seek scientific evidence for the first two claims. I have (weak) empirical evidence to accept them as plausible (I do snore more on my back for instance). What I am asking here is about the third claim.

Does sleeping on your left side put such an extra burden of weight on your heart that it might be unhealthy?

  • 2
    Exercise puts a greater burden on your heart, but I wouldn't say it is bad for the heart. The heart adapts in a positive way. Maybe sleeping on your left will strengthen your heart long term and be beneficial.
    – Kenshin
    Sep 30, 2013 at 4:19
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    I've always heared that sleeping on your left side aswell due to your heart, but i've always figured it was a myth since your heart is mostly in the center anway, and just slightly bigger to the left side.
    – Lyrion
    Sep 30, 2013 at 13:36
  • @Lyrion: That is what I was thinking too. It should make no dfference; but then...
    – yrodro
    Sep 30, 2013 at 15:34
  • @Compro01: Although your comments do not exactly answer my question, they seem to cover close the "heart" of the matter. Care to upgrade to an answer? If there isn't a more exacting one, I should accept yours.
    – yrodro
    Sep 30, 2013 at 18:22
  • With or without the elbow under the ribs? How hard is the mattress? Jan 25, 2014 at 16:43

1 Answer 1



According to this study, patients with congestive heart failure tend to unconsciously avoid sleeping on their left side, whereas healthy patients don't display this avoidance. The reason for this avoidance is unknown, though the paper offers several lines of speculation, ranging from discomfort to various forms of cardiac impairment. As far as I can find, no one has yet followed up on these and even if the reason is the impairment, whether this extends to healthy people is an open question.

Though not directly related to the heart, sleep apnea is frequently (about half of cases) position dependant (i.e. Apneas only occur when in a certain sleep position). In persons with sleep apnea dependant on the left side, sleeping on the left side would have definite deleterious effects, including cardiac ones. This study investigated the frequency of associated positions with sleep apnea, though the actual numbers are behind the paywall and out of my sight.

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    Here is a paywall free version of the study. Oct 14, 2013 at 3:59
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    This is going to be very personal but whenever I sleep on my left side; I feel sick, my shoulder and my chest gets stretched and I can feel my heart bumping very hard which also effects my breathing heavily and I turn right side when I am aware of this situation to relax. So I think this needs to be examined very widely. Hope it has no serious effects. Just people feeling uncomfortable about it. Oct 14, 2013 at 11:04
  • @MrKomandez - Seems the study didn't contain all the data I thought it did from the abstract. It only compared supine vs. non-supine, lumping all other positions into one.
    – Compro01
    Oct 14, 2013 at 21:27

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