People whose bones are thin from osteoporosis often don't know they are at risk because they have no symptoms, says the National Osteoporosis Foundation (NOF). A bone fracture is usually the first sign of the disease.
And, says the NOF, one in five elderly people who suffer broken hips, spine or other broken bones, will not live more than another year, and half will never walk unaided again.
Bone loss happens over such a long period that, by the time a bone breaks, the disease is irrevocably advanced.
To help prevent it, eat a balanced diet rich in calcium and vitamin D; do weight-bearing exercises; don't smoke; drink very little or no alcohol; have your bone density tested; and take medication if you need it.