For most people, the best answer is: sleep on your side , and when in doubt, favor the left side, but adjust based on your health issues and comfort.

Quick Scoop

  • Left-side sleeping often helps with acid reflux/heartburn and is widely recommended in pregnancy because it can improve blood flow and reduce pressure on major vessels.
  • Right-side sleeping may feel better if you have certain heart conditions and can still reduce snoring and sleep apnea compared with sleeping on your back.
  • Side sleeping in general tends to support better spinal alignment and may reduce neck/back pain and snoring compared with back or stomach sleeping, especially with a supportive pillow and mattress.

Simple rule of thumb

  • If you have heartburn/GERD → start on your left side.
  • If you have significant heart disease → many people prefer the right side; follow your cardiologist’s advice.
  • If you are pregnant → aim for the left side, especially in the 2nd and 3rd trimester, and avoid flat-on-the-back sleep.
  • If none of these apply → choose the side that feels best, but keep your spine neutral with a pillow that fills the space from ear to shoulder and, ideally, a pillow between your knees.

If you have chest pain, trouble breathing, severe reflux, or new/worsening symptoms in any position, talk to a doctor urgently.