Osteoporosis

Osteoporosis is a bone disease in which the amount of bone is decreased and the structural integrity of trabecular bone is impaired. Cortical bone becomes more porous and thinner. This makes the bone weaker and more likely to fracture.

A committee of the World Health Organization has defined osteoporosis based on the bone density. Using standardized bone density measurements of the total hip, "normal" bone is greater than 833 mg/cm². "Osteopenia" is between 833 and 648mg/cm². Osteoporosis is lower than 648mg/cm², and "Severe (established) osteoporosis" is when there has been a fragility fracture. Details are explained in the bone density section.