Your bones are in a constant state of renewal — new bone is made and old bone is broken down. When you're young, your body makes new bone faster than it breaks down old bone and your bone mass increases. After the early 20s this process slows, and most people reach their peak bone mass by age 30. As people age, bone mass is lost faster than it's created.
A number of factors can increase the likelihood that you'll develop osteoporosis — including your age, race, lifestyle choices, and medical conditions and treatments.
Your sex: Women are much more likely to develop osteoporosis than are men.
Age: The older you get, the greater your risk of osteoporosis.
Race: You're at greatest risk of osteoporosis if you're white or of Asian descent.
Family history: Having a parent or sibling with osteoporosis puts you at greater risk, especially if your mother or father fractured a hip.
Body frame size: Men and women who have small body frames tend to have a higher risk because they might have less bone mass to draw from as they age.
Courtesy: Mayo Clinic