When should I have a bone density scan?

A bone density scan, or DXA, measures bone mineral density at the spine and hip and reports it as a T-score. It is the test that identifies osteoporosis before a fracture rather than after one, which matters because the first symptom of osteoporosis is usually a broken bone. Two sets of recommendations govern who should have one: the US Preventive Services Task Force for population screening, and the International Society for Clinical Densitometry for clinical indications.

Who should be screened

In its 2025 recommendation, the US Preventive Services Task Force recommends screening for osteoporosis to prevent osteoporotic fractures in women aged 65 years or older, a Grade B recommendation, and in postmenopausal women younger than 65 who are at increased risk, also Grade B. For men, the Task Force concluded that current evidence is insufficient to assess the balance of benefits and harms, a Grade I statement, which means clinical judgement rather than a recommendation against testing. The International Society for Clinical Densitometry recommends testing women aged 65 and older, men aged 70 and older, and younger adults with risk factors.

What counts as increased risk before 65

The situations that move testing earlier are specific: a fracture after the age of 50 from a fall at standing height, long term glucocorticoid use, early menopause including surgical menopause, low body weight, height loss, rheumatoid arthritis, coeliac disease or other malabsorption, hyperparathyroidism, hyperthyroidism, and prior bariatric surgery. Aromatase inhibitors for breast cancer and androgen deprivation therapy for prostate cancer both accelerate bone loss and are their own indication.

How to read the result

The Bone Health and Osteoporosis Foundation sets out the categories used for postmenopausal women and men aged 50 and over: a T-score of minus 1.0 or above is normal, between minus 1.0 and minus 2.5 is low bone mass, and "a T-score of -2.5 or below is a diagnosis of osteoporosis". The International Society for Clinical Densitometry advises measuring bone mineral density at both the posteroanterior spine and the hip in all patients, and using Z-scores rather than T-scores in premenopausal women and men under 50.

If you are a postmenopausal woman under 65, ask for a fracture risk assessment rather than assuming you must wait until 65. If you have had a broken bone from a minor fall after the age of 50, that is an indication for a scan now, whatever your age or sex. Ask for spine and hip together, and keep the report, since future scans are compared against it.