Whether a person develops osteoporosis depends on the thickness of the bones (bone density) in early life, as well as health, diet, and physical activity later in life.

Things that increase your risk for osteoporosis include:

• Your age. Bones naturally become thinner as you get older.
• Having gone through menopause. After menopause, the body makes less estrogen. This hormone protects the body from bone loss.
• Having a lower-than-normal testosterone level.
• Having a family history of osteoporosis. If a parent or sibling was diagnosed with osteoporosis or had broken bones from a minor injury, you are more likely to develop osteoporosis.
• Taking steroids or certain other medicines. Some medicines can cause bone thinning.
• Being inactive due to being in a bed, wheelchair, or other type of chair for long periods of time.
• Having a slender body frame. People with small body frames are more likely to develop osteoporosis.
• Having certain medical conditions. Some medical conditions, such as hyperparathyroidism or an eating disorder, can increase your risk for osteoporosis.
• Having certain surgeries, such as having your ovaries removed before menopause.

Lifestyle factors that increase your risk include:

• Drinking too much alcohol. This can decrease bone formation.
• Smoking. People who smoke may lose bone density faster than nonsmokers.
• Not getting enough calcium and vitamin D. Calcium helps keep your bones strong. And to absorb calcium, your body needs vitamin D.
• Getting little or no exercise. Bone-building exercises like walking, jogging, dancing, or lifting weights help keep bones strong.