Osteoporosis is often called the "silent disease". It is a disease in which bones become fragile and are more likely to break. If not prevented or if left untreated, osteoporosis can progress painlessly until a bone breaks. Most people affected are unaware that their bones are thinning until they experience a break, or notice more gradual signs such as height loss, or curvature of the spine. These broken bones, also known as fractures, occur typically in the hip, spine and wrist.

Any bone can be affected, but of special concern are fractures of the hip and spine. A hip fracture almost always requires hospitalization and major surgery. Spinal or vertebral fractures also have serious consequences, including loss of height, severe back pain and deformity.

Lack of estrogen in the body causes 95 percent of all cases of osteoporosis. Other causes include glucocorticoid and heparin use, hyperthyroidism, and calcium deficiency. Osteoporosis may be or may not be hereditary. Women approaching or experiencing menopause are at increased risk.