If you’re anything like me, you’ve probably never given much thought to the position you adopt while sleeping. After a long day—work, kids, cooking, some relaxation—you’re more likely to fall into bed and crash rather than consciously think about the side you’re lying on.

For most of us, sleep is about getting enough rest to function the next day. But what if the way you sleep could influence your health? Turns out, it can.

While we all have our favorite sleeping styles—whether on our back, right side, or left side—there’s growing evidence that sleeping on your left side offers a surprising range of health benefits. Here’s a closer look at why you might want to reconsider how you catch your z’s.