Osteoporosis is a condition in which the bones become thin and brittle, full of tiny holes like a sponge, so they break more easily. A small fall can break a wrist or a hip; a bone in the spine can crumple with little warning. It is especially common in older women after menopause, but men get it too, and it can come from some medicines or from not using the body much. Though actually, it does not usually hurt until something breaks — that is why people call it a silent problem. You cannot see it from the outside the way you can see a swollen knee. A scan or a break is often how it is found. Do not mix it with osteoarthritis: that one is a worn, painful joint; this one is weak bone. Exercise that loads the skeleton, enough calcium and vitamin D, and sometimes medicine are the usual talk after a diagnosis; the details belong to a doctor, not to a vocabulary note. The name’s middle is about pores — holes — not about being “poor”.