People are surprisingly feisty about their favorite sleeping positions; I'm a back-sleeper myself and I think it's definitely the most comfortable; I have never been able to sleep on my stomach for more than a few minutes, but my partner loves it. And since back-sleepers are known for snoring, I'm probably happier with him on his stomach too.
It turns out that no matter what your personal opinion (or how strongly you hold it!) all sleeping positions have pros and cons. Since getting enough sleep is a problem for so many people, I'd say sleeping whichever way is most comfortable to you is likely what matters most, but if you are having trouble, or waking up in pain on a regular basis, you might want to look at changing the position you fall asleep in. For certain positions, you might even want or need an extra pillow specially designed for it (see ideas below).
Pros: This position is the best for reducing or minimizing face, neck and decolletage wrinkles, since there's no pressure on that skin as you sleep. It's also great for minimizing acid reflux, if you struggle with that issue (be sure to incline the body with the head higher than the stomach to have the most positive effect). As long as your neck is supported and in alignment with the rest of your spine, back sleeping is also considered the best for spine health.
Cons: The worst thing about sleeping on your back is the aforementioned snoring issue, which is even worse for those with sleep apnea or colds.
Tips: For some people, sleeping on their backs can aggravate lower-back issues. Besides doing some stretches like this before bed, you might also consider using a pillow under your knees (there are some designed especially for this use, or you can jury-rig your own).
Pros: Reduced or eliminated snoring, and it's good for blood circulation, so if you have an issue with that, side-sleeping could help. Pregnant women, especially, find it the most comfortable position.
Cons: Side-sleeping will cause fine lines on the side of the face you most often sleep, as well as on the neck and chest. It can also cause shoulder or hip pain in some people.
Tips: To keep the back aligned, and reduce torquing, a pillow like this one can help. When side-sleeping, you should always aim to have the neck in the same plane as the rest of your spine — it's easy to wake up with neck pain from sleeping on your side, specifically when your head is tipped up (forehead higher than the chin), so try to keep this from happening with a pillow of the correct thickness. "You need to fill the space above your shoulder so your head and neck are supported in a neutral position," Ken Shannon, a physical therapist at Brigham and Women's Hospital in Boston told CNN.
To reduce the effects of sleeping on your side on wrinkles, consider a silk pillowcase, which is less drying, pulls at skin less — and musses hair less — than cotton ones.
Pros: Less snoring, as it keeps airways more open; can be fine for those without back issues.
Cons: This position is the worst for wrinkles (as anyone who has woken up with their pillow's wrinkles imprinted on their face can attest). It can also put stress on the lower back, so those with back problems should avoid it. "Stomach-sleeping makes it difficult to maintain a neutral position with your spine," Shannon explained to CNN.
Tips: Placing a thinner pillow under the hips can help keep the back on the same plane as the spine and be less stressful on the spine. Or, try sleeping on your stomach without a pillow at all.