Firmness
Mattress Firmness for Side Sleepers
Side sleeping often increases pressure around shoulders and hips, but body size and personal preference still change what feels comfortable.
Start with pressure tolerance
If your current mattress feels sharply resistant at the shoulder or hip, a softer surface may be worth investigating. If you dislike sinking deeply, move toward a firmer or more responsive design.
Do not treat position as a prescription
There is no universal firmness number for every side sleeper. Use position as one input alongside body size, construction and preference.