What Is Bone Mass?

Bone mass refers to the amount of minerals (mostly calcium and phosphorous) that a specific volume of bone contains. Bone mass is also called bone density or bone mineral density (BMD). A person with low bone density is at high risk for fractures and osteoporosis.

• Bone mass is a measure of the amount of minerals that bone contains.

Bone Mass Tests

• Although different bone mass tests are available, the most widely used is the dual-energy x-ray absorptiometry (DXA) test, which can measure bone mass in the spine, hip or total body.

Test Results

• The result of a bone mass test is a T-score that indicates how much your bone density is above or below the "normal" peak bone density of a 30-year-old adult. A T-score between +1 and -1 is normal bone density. A T-score between -1 and -2.5 indicates low bone density or osteopenia. A T-score of -2.5 or lower indicates osteoporosis.

Osteoporosis

• With osteoporosis, bones are fragile and more likely to break. Although any bone can be affected, hip fractures that require major surgery are common. Also serious are fractures of the bones in the spine, which can cause loss of height, severe back pain and deformity.

Causes of Low Bone Mass

• According to the National Institute of Arthritis and Musculoskeletal and Skin Diseases, causes of low bone mass include heredity, not developing optimal peak bone mass when young, a medical condition or medication that negatively affects bone, and unusually accelerated bone loss.

Prevention

• Recommended ways to prevent low bone mass include eating foods that contain lots of calcium and vitamin D, doing weight-bearing exercise (such as walking, jogging or dancing), not smoking and not drinking alcohol in excess. If you have osteopenia, your doctor may suggest drugs to prevent more bone mass loss that could lead to osteoporosis.