A memory foam mattress may reduce back pain for some people, but it can also cause back pain if the model is not suitable. The main reason is usually poor spinal alignment. If the foam layer is too soft or too thick and the support core underneath is weak, the lower back can sink, increasing stress—especially for back sleepers. Memory foam also molds closely to the body, which may make repositioning harder for people who move a lot during sleep, potentially leading to morning stiffness. A well-designed memory foam mattress, however, can relieve pressure points, promote muscle relaxation, and reduce pain symptoms. That’s why density, firmness, zoning, and having a trial period are critical when choosing. If discomfort persists, pillow height and sleep posture should also be reviewed.