Bone Density: What Weakens Bones, How It's Measured, and How to Keep Them Strong

Bones are living tissue. To keep them strong, the body constantly breaks down old bone and replaces it with new. When more is broken down than replaced, you lose bone density, also called bone mass.

Bone density measures how much calcium and other minerals your bone contains. Denser bones tend to be stronger and less likely to break; losing density weakens them.

Not everyone with low bone mass develops osteoporosis, but they are at higher risk.

What makes you lose bone density

Bones naturally become less dense with age. Other things raise the risk:

• a family history of osteoporosis or low bone mass
• not building good bone mass when young
• certain medical conditions: endocrine diseases, some digestive diseases, rheumatoid arthritis, certain cancers, HIV, and anorexia nervosa
• certain medicines: corticosteroids, proton pump inhibitors (used for GERD), and medicines for epilepsy
• smoking
• long-term heavy drinking
• physical inactivity, or long periods of bed rest

How it's measured

A bone density scan is the best way to check bone health. It compares your bone density with that of a healthy person of the same age and sex, and can show:

• whether your bone density is low
• whether you have osteoporosis
• your risk of breaking a bone
• whether osteoporosis treatment is working

Keeping bones strong

The most important thing, to keep bones strong and help prevent osteoporosis, is a healthy diet rich in calcium and vitamin D. Regular physical activity, limiting alcohol and not smoking help too. Sometimes a health care provider will prescribe medicine to prevent osteoporosis.

Sources

Based on the MedlinePlus health topic "Bone Density," National Library of Medicine, drawing on the National Institute of Arthritis and Musculoskeletal and Skin Diseases; a work of the United States government in the public domain.