A DEXA scan usually assesses or measures bone density. It can also be used to determine body composition, such as the percentage of lean muscle and fat.
The dual-energy X-ray absorptiometry (DEXA) scan uses two low-energy X-ray beams, which doctors direct toward the bones. Using dual-energy levels separates the images into two components, including soft tissue and bone.
When determining whether a person has low bone density or whether their condition is getting worse, a DEXA scan tends to be more accurate than a typical X-ray because it can detect even small changes in bone loss.