Strong bones are important for your health. A bone mineral density (BMD) test is the best way to measure your bone health. It compares your bone density, or mass, to that of a healthy person who is the same age and sex as you are. It can show
Low bone mass that is not low enough to be osteoporosis is sometimes called osteopenia. Causes of low bone mass include family history, not developing good bone mass when you are young, and certain conditions or medicines. Not everyone who has low bone mass gets osteoporosis, but they are at higher risk for getting it.
If you have low bone mass, there are things you can do to help slow down bone loss. These include eating foods rich in calcium and vitamin D and doing weight-bearing exercise such as walking, tennis, or dancing. In some cases, your doctor may prescribe medicines to prevent osteoporosis.
NIH: National Institute of Arthritis and Musculoskeletal and Skin Diseases