When choosing the right mattress for your needs it's essential to consider its firmness. Mattresses can be divided into three categories depending on the level of support they provide: soft, medium and firm. If you're currently sleeping on a very soft mattress, maybe you should replace it with one that provides a more firmer sleeping surface. But, keep in mind that a firm mattress doesn't always mean that you will get the best support for your spine. Sleeping on a very firm surface can be uncomfortable and even worsen your back pain. If you prefer to sleep on the side then you should definitely avoid firm mattresses, since they can create pressure points and strain your muscles and joints. A mattress that has a medium level of firmness is the best of both world since it can provide a comfortable sleeping surface and a lot of support in almost all sleeping positions. A soft mattress would generally be very comfortable to sleep on, but usually lacks to provide adequate support that can keep your body in a healthy sleeping position.