Most people ignore mattresses completely, but they really shouldn’t. A good rhythm is to vacuum your mattress every 1–3 months, and do a deeper clean at least once a year. Over time, mattresses collect dust, dead skin, hair, and sometimes crumbs or spills. It doesn’t look dirty from outside, but your nose and allergies eventually notice.
When changing bedsheets, give the mattress a quick inspection. If you see lint, hair or dust, pull out the vacuum with a brush attachment and run it slowly across the surface, especially along seams and edges. For stains, spot-clean gently with a mild solution and avoid soaking the mattress; too much moisture can cause mould inside.
Once or twice a year, if possible, air the mattress out. On a dry, sunny day, open windows wide or place it upright for a few hours so air can circulate. Flipping or rotating it, if the design allows, also helps with comfort and longevity.
You spend a huge chunk of life lying on that surface. Giving it some attention now and then is good for both health and sleep.