The bone density test diagnoses osteopenia and osteoporosis, according to the National Osteoporosis Foundation. It is also used to determine whether bone density is improving, getting worse or remaining static. If a person is being treated for bone density issues, the test indicates how well treatment is working.
The bone density test measures the amount of calcium and other minerals in a section of bone, explains Mayo Clinic. The higher the bone mineral content, the stronger the bones and the less likely they are to fracture.
Bone density test results are reported using T-scores, which indicate a person's bone density in comparison to that of the average 30-year-old adult, notes the National Osteoporosis Foundation. A T-score of -1 and above indicates normal bone density; a T-score between -1 and -2.5 indicates low bone density, or osteopenia; and a T-score below -2.5 indicates osteoporosis.
A low bone density result does not necessarily indicate osteoporosis is certain to develop, but it means osteoporosis may develop if bone loss continues, states the National Osteoporosis Foundation. Postmenopausal women and men over 50 with T-scores of -1 and above normally do not require treatment. Those with T-scores between -1 and -2.5 may require medication if they have certain risk factors. Those with T-scores below -2.5 should take medication for osteoporosis.