Key takeaways:
The DEXA (dual-energy X-ray absorptiometry) scan is a special X-ray test that looks for bone thinning and loss.
Healthcare professionals recommend DEXA scans for women 65 years and older, and people who are at high risk for developing osteoporosis or fractures.
How often you get a DEXA scan depends on the results of your first test and your overall risk for bone loss.
A DEXA (dual-energy X-ray absorptiometry) scan is a special type of X-ray that measures bone density (strength). In short, it’s a bone density test that measures your bone mass. DEXA scans can be really useful for people at risk for osteoporosis. Osteoporosis is a condition where bones become thinner and weaker. People with osteoporosis are more likely to have bone fractures.
Let’s take a look at how DEXA scans work, why you might need one, and how to prepare if you do.
What is a DEXA scan?
A DEXA scan is a type of imaging test, also called a bone density scan or bone density test. It uses X-rays to measure bone density.
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When you get a DEXA scan, a machine takes X-rays of your lower back, hip, or forearm. The images get processed and the software calculates your bone density.
Your bone density is an important indicator of your overall bone health. A low bone density is a sign of bone thinning and bone loss.
In addition to measuring bone density, DEXA scans can also estimate muscle mass and body fat percentage. So a full-body DEXA scan can give a report of body composition.
What is a DEXA scan used for?
The most common reason people get a DEXA scan is to check their bone health. DEXA scans look for:
Bone thinning and weakness (osteopenia)
Bone loss (osteoporosis)
Osteopenia can progress to osteoporosis. And osteoporosis can eventually lead to fractures and other bone problems.
The hope is that people with low bone density can be diagnosed and start treatment early. This can help increase bone density and prevent fractures in the future.
People being treated for osteoporosis also have repeat bone density scanning to monitor how they’re responding to treatment.
Who needs a DEXA scan?
A healthcare professional may recommend a DEXA scan if you’re at high risk of developing osteopenia or osteoporosis. Some things that increase your risk include:
Age: As you get older, your bones start to lose strength. The DEXA screening guidelines issued by the U.S. Preventive Services Task Force recommends bone density testing for all women over age 65 years.
Diet and exercise: People who don’t move as much, don’t get enough calcium in their diets, or have vitamin D deficiency are more likely to have bone loss.
Hormone changes: Changes in estrogen levels can increase bone loss. This can affect people going through menopause or receiving certain hormone-based medications.
Smoking and heavy alcohol use: These are linked to decreased bone density.
Prior bone fractures: Having a history of bone fractures as an adult, especially hip fractures, can be a sign of bone thinning.
Medications: Certain medications like steroids can lead to bone loss.
Medical conditions: People with diabetes and certain liver, kidney, parathyroid, and thyroid conditions can develop osteoporosis.
How much does a DEXA scan cost?
The average cost of a DEXA scan is more than $300. But the amount you end up paying depends on your health insurance and the reason the test is being done.
For example, DEXA scans for bone density can be completely covered by Medicare if you’re postmenopausal and older than 65 years. Many insurance companies also cover DEXA scans if you’re at risk for developing osteoporosis.
Check with your health insurer to see what your cost will be. Or you can contact imaging centers directly for a good faith estimate if you plan to pay out of pocket.
How do I prepare for a DEXA scan?
A DEXA scan is a routine test that can be done at many imaging centers. The bone density scan procedure is pretty simple. To prepare for your bone density scan, you should:
Stop taking any calcium supplements 24 hours prior to the scan.
Avoid scheduling imaging studies that involve contrast dyes or barium within 2 weeks of the scan.
Make sure you aren’t pregnant, because you’ll need to reschedule if you are.
If you’re having your body composition measured (not just your bone density), you may need to fast (stop eating) before the scan. Be sure to follow the imaging center’s directions.
What should I expect during a DEXA scan?
On the day of the scan, wear loose, comfortable clothing without any metal (such as zippers), which could affect the test results. Some centers may ask you to change into a gown. You won’t be able to keep anything in your pockets, such as your phone or keys.
For the test, you’ll be asked to lie on your back on a padded table. The imaging machine, called a C-arm, will pass over your hips and lower back. Your legs will be propped up on a box so that your pelvis and lower back are flat during the test.
When it’s time to look at your hips, you might be asked to turn your foot and leg. Most centers have braces to help you achieve the right position.
The entire process will take about 10 to 20 minutes, and then you’ll be able to go home.
What do my DEXA scan results mean?
Once your DEXA scan is complete, a radiologist will review the results and calculate your bone density.
Your DEXA scan results are reported as a T-score. A T-score compares your bone density test results to that of a healthy 30-year-old adult who has normal low bone density (score 0). Here’s how to interpret your T-score:
A T-score that’s between 0 and -1 is normal.
A T-score between -1 and -2.5 indicates osteopenia.
A T-score of -2.5 or lower indicates osteoporosis.
The lower your T-score, the more likely you are to develop bone fractures.
What are the benefits and risks of a bone density scan
There are few risks associated with getting a DEXA scan. The main one is exposure to a small amount of radiation, less than that of a chest X-ray. You must also lie flat and be still for the scan, which may be difficult for some people.
The benefits are that it’s relatively quick, painless, and noninvasive. It doesn’t require anesthesia. A DEXA scan is an easy way to check on your bone health.
How often should I get a DEXA scan?
It depends. People who are at increased risk for bone loss should have a DEXA scan at least once to screen for osteoporosis. After that, how often you need a DEXA scan depends on several factors, such as:
The T-score of your first DEXA scan
Whether you’re taking medication for osteoporosis
Your risk factors for bone loss
Your overall health
This information will determine how often you need a DEXA scan. For example, if your DEXA scan finds osteoporosis (T-score less than -2.5), a DEXA scan may be repeated in 2 years to see how you’re responding to treatment. But if your first DEXA scan is normal and you don’t have many risk factors for bone loss, you may not need to repeat a DEXA for 10 years or more.
Frequently asked questions
Osteoporosis typically doesn’t cause any symptoms as it’s developing. But as it progresses, osteoporosis in the spine can lead to loss of height, stooped posture, and back pain. A bone fracture is often the first sign of osteoporosis.
A central DEXA scan is the most common. The imaging machine that performs the central DEXA scan is what you see in hospitals and imaging centers. It measures bone density in the center of the body, specifically the spine and hip.
A peripheral DEXA scan (or p-DEXA) is done by a smaller, portable device. It measures bone density in body parts such as the wrist, heel, or finger, but these results shouldn’t be used for diagnosis.
Osteoporosis typically doesn’t cause any symptoms as it’s developing. But as it progresses, osteoporosis in the spine can lead to loss of height, stooped posture, and back pain. A bone fracture is often the first sign of osteoporosis.
A central DEXA scan is the most common. The imaging machine that performs the central DEXA scan is what you see in hospitals and imaging centers. It measures bone density in the center of the body, specifically the spine and hip.
A peripheral DEXA scan (or p-DEXA) is done by a smaller, portable device. It measures bone density in body parts such as the wrist, heel, or finger, but these results shouldn’t be used for diagnosis.
The bottom line
A DEXA scan is a test to determine your bone density and body composition. Not everyone needs a DEXA scan. As you get older, you might need one to check your bone health, because bone loss becomes more common with age. You can speak with your primary care provider about your risk of osteoporosis and whether a DEXA scan might be right for you.
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References
Camacho, P. M., et al. (2020). American Association of Clinical Endocrinologists/American College of Endocrinology Clinical Practice Guidelines for the Diagnosis and Treatment of Postmenopausal Osteoporosis—2020 Update. Endocrine Practice.
Leslie, W. D., et al. (2021). Serial bone density measurement for osteoporosis screening. JAMA.
Medicare.gov. (n.d.). Dual-energy x-ray absorptiometry (dxa), bone density study, 1 or more sites; axial skeleton (eg, hips, pelvis, spine).
MedlinePlus. (2024). Bone density scan.
National Institute of Arthritis and Musculoskeletal and Skin Diseases. (2025). Bone mineral density tests: What the numbers mean.
Pouresmaeili, F., et al. (2018). A comprehensive overview on osteoporosis and its risk factors. Therapeutics and Clinical Risk Management.
RadiologyInfo.org. (2024). Bone density scan (DEXA or DXA).
Shepherd, J., et al. (2017). Body composition by DXA. Bone.
Siemens Healthineers. (n.d.). Surgical C-arms and navigation.
U.S. Preventive Services Task Force. (2025). Osteoporosis to prevent fractures: Screening.
