What Is a Bone Mineral Density Test?
 
A bone mineral density test uses X-rays to measure the amount of minerals — namely calcium — in your bones. This test is important for people who are at risk for osteoporosis, especially women and older adults.
 
The test is also referred to as dual energy X-ray absorptiometry (DXA). It is an important test for osteoporosis, which is the most common type of bone disease. Osteoporosis causes your bone tissue to become thin and frail over time and leads to disabling fractures.
 
Why a Bone Mineral Density Test Is Performed
 
The National Institutes of Health (NIH) recommend that the following people get preventive screenings for bone mineral density:
all women over the age of 65
women under the age of 65 who have a high risk of fractures
Women have an increased risk for osteoporosis if they smoke or consume three or more alcoholic beverages per day. They are also at an increased risk if they have:
chronic kidney disease
early menopause
an eating disorder resulting in low body weight
a family history of osteoporosis
a “fragility fracture” (a broken bone caused by regular activities)
rheumatoid arthritis
significant height loss (a sign of compression fractures in the spinal column)
very inactive physically and do minimal weight bearing activities
 
Risks of a Bone Mineral Density Test
Because a bone mineral density test uses X-rays, there is a small risk associated with radiation exposure. However, the radiation levels are very low. Experts agree that the risk posed by this radiation exposure is far lower than the risk of not detecting osteoporosis before you get a bone fracture.