Bone Density Scan: MedlinePlus Medical Test

What is a bone density scan?

A bone density scan, also known as a DEXA scan, is a type of low-dose x-ray test that measures calcium and other minerals in your bones. The measurement helps show the strength and thickness (known as bone density or mass) of your bones.

Most people’s bones become thinner as they get older. When bones become thinner than normal, it’s known as osteopenia. Osteopenia puts you at risk for a more serious condition called osteoporosis. Osteoporosis is a progressive disease that causes bones to become very thin and brittle. Osteoporosis usually affects older people and is most common in women over the age of 65. People with osteoporosis are at higher risk for fractures (broken bones), especially in their hips, spine, and wrists.

Other names: bone mineral density test, BMD test, DEXA scan, DXA; Dual-energy x-ray absorptiometry