Osteoporosis is a disease that causes bones to become more porous, gradually making them weaker and more brittle. ("Osteo" means bone; "porosis" means porous.) Our bodies go through a continuous bone-building cycle, in which old bone is broken 
down and new bone is formed. Osteoporosis is caused by an imbalance in this cycle, in which too much bone is broken down and not completely built.
Today, an estimated 28 million Americans have or are at risk of osteoporosis – 80 percent are women. Yet only a relatively small number of men and women with osteoporosis have been diagnosed or treated.
Why is this?
Few women and men experience symptoms in the early stages of this bone-thinning disease. Also, many women and men believe that if they simply watch their diet and exercise regularly, they won’t be affected.
Signs and symptoms
Early on, osteoporosis is a silent disease, so you may not see any signs.
Eventually, it can lead to broken bones or the disfiguring "dowager’s hump" in some women. The good news is, if osteoporosis is detected early enough, its effects may be prevented.
