Tests done to evaluate the density of bones. Bone density testing is used to measure bone strength, predict fracture risk, and assess the degree of osteoporosis, a condition that results in the bones slowly losing mass and becoming more susceptible to fractures. A certain amount of bone loss is a normal consequence of aging in both men and women. Done periodically, bone density tests can help determine whether and how quickly the bones are losing calcium. Bone density testing should be considered if a woman is older than 40 years and has already experienced a bone fracture; has a close female relative who has had osteoporosis or a bone fracture; takes medication (such as corticosteroids or antiseizure medication) that accelerates bone loss; has a low body weight or a slight build; has a light complexion; or has a history of heavy drinking or smoking. Men are at less risk of osteoporosis than women but should be tested if they have a risk factor for osteoporosis such as taking corticosteroids.