Osteoporosis is a common condition characterized by a decrease in the density of bone, decreasing its strength and resulting in fragile bones. People with osteoporosis have a higher risk of fractures. Wrist fractures, hip fractures and fractures of the vertebrae (bones in the spine) are the most common type of breaks that affect people with osteoporosis. 

Osteoporosis is much more common in women than in men. Bone mass (bone density) decreases after 35 years of age, and bone loss occurs more rapidly in women over age 50 after menopause, when monthly periods stop and the ovaries stop producing an estrogen.