Bone Densitometry: What It Is and What to Expect
Medically reviewed by Raghuveer Boddireddy, MD, Interventional Radiology. Last reviewed: October 23, 2026.
What kind of doctor provides Bone Densitometry?
A radiologist, a doctor trained to read x-ray pictures, studies the images from a bone densitometry scan. A technologist, a trained imaging worker, runs the x-ray machine. The report then goes to your primary care or referring doctor. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What it is
Bone densitometry is also called a DXA or DEXA scan. It is also called a bone density test. It uses a very small dose of ionizing radiation, the energy in x-rays, to take pictures inside the body. The pictures usually show the lower spine and hips, and they help measure bone loss. It is the most commonly used and most standard method for diagnosing osteoporosis. Osteoporosis is a condition in which bones get thinner, more fragile and more likely to break.
The machine sends a thin beam of low-dose x-rays through the bones being examined. Most scanners are central devices, which measure bone density in the hip and spine.
Why a doctor might recommend it
Doctors most often use this scan to find osteoporosis. The scan can also assess your risk of fractures, which are broken bones. Testing is strongly recommended for a woman past menopause who is not taking estrogen.
How to prepare
This exam needs little to no special preparation.
- Do not take calcium supplements for at least 24 hours before the exam.
- Wear loose, comfortable clothing without metal zippers, belts or buttons.
- Remove jewelry, dental appliances, eyeglasses and any metal objects that might block the images.
- Tell your doctor and the technologist if you might be pregnant.
- Also tell them if you recently had a barium exam or a contrast injection for a CT or radioisotope scan, which are other imaging tests.
What happens during it
Your doctor will likely do this exam on an outpatient basis, which means you go home the same day. In a central scan, you lie on a padded table. An x-ray generator is below you and a detector is above you. For the spine, your legs are supported on a padded box to flatten the pelvis and lower spine. You must hold very still and may need to hold your breath for a few seconds. Peripheral tests are simpler. A finger, hand, forearm or foot goes into a small device that gives a reading within a few minutes.
Recovery
Bone density tests are a quick and painless procedure. No complications are expected with this scan. Your primary care or referring doctor will discuss the results with you.
Risks and side effects
There is always a slight chance of cancer from excessive exposure to radiation. The amount of radiation in medical imaging is small, so the benefit of an accurate diagnosis far outweighs the risk. Women should always tell their doctor and x-ray technologist if they are pregnant.
A DXA test cannot predict who will have a fracture, but it can show a relative risk. It is of limited use in people with a spinal deformity or past spinal surgery.
Who performs it
Rheumatologists (joint doctors) and endocrinologists (hormone doctors) also read DXA scans.
Common questions
How long does a bone densitometry scan take?
A bone densitometry scan usually takes 10 to 30 minutes, depending on the equipment and the body parts being examined.
What do the T score and Z score mean?
The T score compares your bone with a young adult of the same gender who has peak bone mass. A T score of -1 and above is considered normal. A score between -1.1 and -2.4 is classed as osteopenia, which means low bone mass. A score of -2.5 and below is defined as osteoporosis. The Z score compares your bone with other people of your age group, size and gender.
How often will I need another scan?
Routine scans every two years may be needed to see a big change in bone mineral density.
Who should get a bone densitometry scan?
The US Preventive Services Task Force says women over age 65 should have the test. It also recommends testing for women younger than 65 who have gone through menopause and are at increased risk of an osteoporosis-related fracture. More research is needed before it can make a recommendation about screening men.
How does a direct primary care or concierge doctor fit in?
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. The report from your scan goes to your primary care or referring doctor, who discusses the results with you.
Sources
- RadiologyInfo.org - Bone Density Scan (DEXA or DXA)
- MedlinePlus - Bone mineral density test
- National Institute of Arthritis and Musculoskeletal and Skin Diseases - Bone Mineral Density Tests: What the Numbers Mean
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
