Thomas Høegh Reisenhus, sleep specialist and sleep counselor at TEMPUR says your mattress should adapt to you, distribute your weight evenly, keep your spine straight, and absorb pressure to aid comfort and relieve pain.
'A mattress that is too soft will cause your back or hips to slouch and your spine to fall out of alignment,' he explains. 'A mattress that is too firm will put too much pressure on your joints, potentially causing discomfort or pain.'