Can an old mattress cause back pain?

Yes, an old mattress can cause back pain. Once its foam compresses or its coils soften, the mattress stops holding the spine in a neutral line, and the strain shows up as morning stiffness.

A worn mattress sags where your hips and shoulders press most, so the lower back sinks out of alignment for hours each night. Back sleepers and stomach sleepers feel this first, because they need a medium to firm surface to keep the spine level. Replacing an aging mattress is often the simplest fix for waking up sore.

Most side sleepers prefer a soft to medium mattress; most back and stomach sleepers prefer medium to firm.
Buyers commonly ask how often to replace a mattress, because construction type changes how long support holds.
Hybrid mattresses pair individually pocketed coils with 2 or more inches of foam comfort layers for lumbar support.
Zoned support firms up the lumbar and hip region, which helps keep the spine neutral for back-pain sleepers.