What should you know about bone marrow density test?

A bone density test, usually a DEXA scan, measures bone mineral density rather than the bone marrow itself. It helps a clinician assess bone strength and the possibility of osteoporosis or fracture risk. The scan commonly examines the hip and lower spine using low-dose X-rays. It does not sample marrow and is different from a bone marrow biopsy.

DEXA compares the mineral content of your bones with reference values. The report may include a T-score, which compares your result with that of a healthy young adult, and a Z-score, which compares it with people of a similar age and sex. A lower result can support a diagnosis of reduced bone density, but interpretation also considers previous fractures, medicines, menopause, medical conditions, and other risk factors. The scan does not by itself explain why bone density has changed.

Tell the imaging team if you may be pregnant, recently had a contrast examination, or take calcium supplements. Follow the centre's instructions about clothing, metal fasteners, and whether to pause a supplement before the appointment. During the scan, you lie still on an open table while the scanner passes over the relevant area. Afterwards, discuss what the result means for you. Management may include weight-bearing activity, adequate calcium and vitamin D, fall prevention, review of medicines that affect bone, or prescription treatment when appropriate.

A bone density scan is generally planned rather than urgent. Seek prompt assessment after a fall or injury if you have severe pain, cannot bear weight, notice a limb deformity, or develop new weakness or numbness. Arrange a routine medical review if you have lost height, developed persistent back pain, sustained a fracture after a minor impact, or use medicines that can weaken bone. These concerns may require examination or other imaging instead of waiting for a DEXA appointment.

Ask which body areas will be scanned, how your result compares with any previous scan, whether another condition or medicine could be affecting your bones, and when reassessment would be useful. If treatment is proposed, ask about its purpose, possible side effects, monitoring, and the changes that would prompt an earlier review.