The bone disease osteoporosis is caused by more bone calcium being resorbed than being deposited. This imbalance results in a progressive loss of bone density and a thinning and weakening of bone tissue. Osteoporotic bones are more porous and therefore more vulnerable to fracture.
Review Date: 1/18/2013
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital.