Hi, Sorry to hear you are in pain! Can you give us a bit more information? Are you in pain from pressure or pain from a lack of support?

Usually, if you are lightweight, you will want a softer mattress. Someone with little body fat tends to feel pressure more. But you want to be careful to not go so soft that you lose support. I would recommend staying away from anything with coils. A memory foam mattress or all latex would be best. On the latex I recommend something that is made with zoned latex, as a solid piece of latex that is not zoned will add more pressure in the hips and shoulders.

When you're small, it's more difficult to enjoy the benefit of the support beneath the top comfort layers of a mattress. Memory foam tends to contour beautifully (I always prefer plant-based foams), but you might benefit from an individually pocketed coil with medium and medium plush layers above. I tend to recommend a medium mattress with firm support, plus a wool topper. Wool is so forgiving and creates such a soothing surface layer. It achieves, what people have described to me, a cloud-like or floating feel, which helps relieve pressure points. I would avoid firm (hard) memory foam and/or latex. Best to go with a more inviting comfort.