A bone-density scan is a way to measure the strength of your bones. The test, called a DEXA scan, is a kind of X-ray. The main reason to have the test is to find and treat serious bone loss, called osteoporosis, and prevent fractures and disability.
Join today and get instant access to all test results and research.
A DEXA scan measures the mineral density of the bone, usually in the hip and spine. Results are given as a “T-score”, which is your bone density compared with a normal young adult of the same sex.
Most people have no bone loss or have mild bone loss (called osteopenia). Their risk of breaking a bone is low so they do not need the test. They should exercise regularly and get plenty of calcium and vitamin D. This is the best way to prevent bone loss.
A bone-density scan gives out a small amount of radiation, but radiation exposure can add up. The effects can add up in your body over your life, so it is best to avoid it if you can.
Women should get a DEXA scan at age 65, and men age 70 and up. They may want to talk with their health care providers about the risks and benefits before deciding. Younger women and men aged 50 to 69 should consider a scan if they have risk factors for serious bone loss. Common risk factors include:
Most changes in bone density do not happen quickly. There is often no benefit having a follow-up DEXA scan for at least 5 years. If your T score from your first scan was 2.00 or more, you do not need another scan for 5 years. You may need a follow-up scan sooner if you have risk factors for bone loss, such as:
The following steps can help you build bone:
If you have questions about your symptoms or the medicines managing your symptoms, speak with your health professional.
You can also download this information as a pdf (479 KB).
Developed by Choosing Wisely New Zealand, 2018. Adapted from Choosing Wisely Canada and Choosing Wisely USA/Consumer Reports (2016) “Bone density tests: when you need them and when you don’t” and BPAC New Zealand (2008) “Prevention of Osteoporosis”. Choosing Wisely does not assume any responsibility or liability arising from any error or omission or from the use of any information in these resources.
This article is part of our content on Choosing Wisely, a campaign encouraging a change in thinking by health professionals and consumers to avoid unnecessary medical intervention.