Preparing for a medical test often triggers health anxiety, making it easy to worry about hidden conditions and care needs. While a DEXA scan is the gold standard for spotting osteoporosis and weak bones, patients often wonder if it reveals more, like bone cancer or tumors.
In reality, these scans focus strictly on mineral density. For concerns involving stress or suspicious growths, medical experts typically turn to an ultrasound or MRI. Beyond the clinic, supporting your skeleton through a diet rich in calcium and vitamin D, and exploring natural remedies for bone strength, can offer peace of mind.
Overview
The short answer is no, a DEXA scan is not designed to find cancer. Its main job is to measure the strength of your bones. It looks for osteoporosis, which is a condition that makes bones brittle, as explained by the American Cancer Society.
However, in rare cases, a DEXA scan might reveal an area that appears unusual. If a cancer has spread to the bone or if a tumor has destroyed some bone, the scan might pick up that change in density. But healthcare experts do not use DEXA scans to screen for cancer. As PubMed Central explains, oncologists rely on other specific imaging tests for cancer diagnosis.
What is a DEXA scan?
DEXA stands for Dual-Energy X-ray Absorptiometry. That is a big name, but the test is actually straightforward. As noted by the Mayo Clinic, it is the gold standard for measuring bone mineral density (BMD). Medical professionals use it to see if you are at risk of breaking a bone.
The Mayo Clinic also explains that it is most commonly used for older women, who are at the highest risk for bone loss after menopause.
How it works
The machine is large and open. You lie down comfortably on a padded table. An arm passes over your body during the scan. It does not touch you at any point. The machine sends two different X-ray beams through your body. One beam is absorbed by soft tissue, like muscle and fat. Your bone absorbs the other beam. The machine then performs a mathematical calculation. It subtracts the soft tissue amount from the total. What is left is the specific density of your bone.
If your bone blocks a lot of the X-ray, your bones are dense and strong. If the X-ray goes right through, your bones are thin and weak. The Cleveland Clinic notes that a DEXA scan, also known as a bone density test, is a painless and quick procedure. It usually takes about 10 to 20 minutes to complete.
What a DEXA scan can detect
A DEXA scan is a specialized scan. It excels at one thing: identifying osteoporosis. This is when bones lose density and become likely to break. It also detects osteopenia, which is the stage preceding osteoporosis. It means your bones are weaker than usual but not yet breaking.
Some modern DEXA scans can also measure body composition. This means they can tell you how much body fat and muscle mass you have. However, can it detect cancer? Sometimes, cancer cells spread to the bones. This is called metastasis. If the cancer eats away at the bone, it creates a “hole” or a weak spot. This is called a lytic lesion.
Because a DEXA scan measures density, it might notice that one spot of bone is much less dense than the bone next to it. So, while it does not “see” the tumor, it sees the damage the cancer caused. According to Johns Hopkins Medicine, this bone densitometry procedure is excellent for measuring bone density. However, it is not the primary tool for investigating bone tumors. You might need other imaging tests for that specific purpose.
Limitations
The DEXA scan has some significant limitations when it comes to cancer. First, it is a 2D image that takes a flat picture of a 3D object. This means things can hide behind the bone. Second, it has low resolution. Compared to other scans, DEXA pictures are blurry. They are not intended to reveal minute details.
Third, it cannot distinguish between causes. If the scan reveals a dense spot, it may indicate a healed fracture. It could also be arthritis or a bone tumor. The scan cannot distinguish between these conditions. Medical experts call these “incidental findings.” This means they found something they were not expecting to find. If they see this, they will always order a better test to confirm it.
Studies from the National Institutes of Health (NIH) emphasize that additional imaging is almost always required to diagnose the cause of density changes.
Risks and safety considerations
DEXA scans are very safe. They use radiation, like a standard X-ray. However, the amount is minimal. In fact, the radiation from a DEXA scan is about the same as what you get from the environment in a typical day.
However, RadiologyInfo.org advises that if you are pregnant, you should tell your healthcare professional. Even small amounts of radiation should be avoided during pregnancy if possible.
Alternatives or additional tests
If a doctor suspects you have cancer in your bones, they will not use a DEXA scan. They have much better tools. Among them are bone scans, or nuclear medicine. In this test, a small amount of radioactive dye is injected into your vein. The dye travels to areas of active or damaged bone. It lights up “hot spots” on the scan. According to the U.S. Centers for Disease Control and Prevention, this test is effective for detecting cancer that has spread to the bones.
Another option is a CT scan, which provides a 3D X-ray by taking hundreds of pictures from different angles. It gives a very detailed map of the bone structure. As for MRI, these use magnets, not radiation, and are the best way to see bone marrow inside the bone. It can find tumors before they even damage the hard bone.
Ultimately, a biopsy is the only way to know for sure. A doctor takes a tiny sample of bone tissue to examine under a microscope. If you have had a bone density scan at another clinic, bring those results with you. The medical specialist needs to compare the change in your bones over time. Seeing a sudden drop in density is more informative than seeing just one number.
What is bone cancer pain like?
Since a DEXA scan is not a cancer test, it is essential to pay attention to your body. Bone cancer, or cancer that has spread to the bone, usually hurts. The pain is often described as a dull ache. It typically starts in one specific area. It is not like the all-over ache of the flu.
A key sign is that the pain worsens at night – it might even wake you up. Pain from regular exercise typically improves with rest. Bone cancer pain often stays the same or gets worse when you rest. MedlinePlus states that deep aches in long bones (such as the thigh or arm) that do not subside should always be evaluated by a doctor.
What problems can a DEXA scan show?
While cancer is rare, DEXA is excellent at finding other common problems. According to a National Library of Medicine publication, the bones in the spine can sometimes collapse without being noticed. A DEXA scan can sometimes catch these “silent” fractures.
Sarcopenia is the medical term for muscle loss. Some advanced scans can tell if you are losing too much muscle as you age. Additionally, arthritis can sometimes make the bones appear denser on a scan. This can actually trick the machine. However, radiologists are trained to look for these tricks. They check the image to make sure the “strong bone” is not actually just bone spurs from arthritis.
“Bone remodeling maintains strong bones. Therefore, any activity that puts your bones to work stimulates them,” Dr. Justus Rabach, MD, explains. “Something as simple as daily walking can help. Keep moving properly to get results and stay injury-free.”
Bottom line
A DEXA scan is designed to check for osteoporosis and weak bones, not to find tumors or cancer. While it can sometimes show “incidental” signs of cancer, like a spot of unusual density or a bone destroyed by a tumor, it is not reliable for diagnosis.
If you have deep bone pain that gets worse at night, do not rely on a bone density test; ask your doctor for an MRI or a nuclear bone scan instead.
Frequently Asked Questions
Can DEXA show tumors?
Generally, no; DEXA images are low-resolution and cannot clearly distinguish a tumor from other bone issues.
What is the biggest indicator of bone cancer?
The Mayo Clinic reports that the most common symptom is persistent pain in the affected bone, which worsens at night or with activity and does not improve with rest.
Citations
American Cancer Society. Osteoporosis. Cancer.org. Published 2025. https://www.cancer.org/cancer/managing-cancer/side-effects/osteoporosis.html
Wang T, Ni Y, Liu L. Innovative Imaging Techniques for Advancing Cancer Diagnosis and Treatment. Cancers. 2024;16(14):2607-2607. doi:https://doi.org/10.3390/cancers16142607
Mayo Clinic. Bone density test. Mayoclinic.org. Published September 21, 2022. https://www.mayoclinic.org/tests-procedures/bone-density-test/about/pac-20385273
Cleveland Clinic. DEXA Scan (DXA): Bone Density Test, What Is It & How It’s Done. Cleveland Clinic. Published 2020. https://my.clevelandclinic.org/health/diagnostics/10683-dexa-dxa-scan-bone-density-test
Johns Hopkins Medicine. Bone Densitometry. John Hopkins Medicine. Published 2019. https://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/bone-densitometry
Esteves-Oliveira M, Yu H, de Paula Eduardo C, et al. Screening of CO 2 Laser (10.6 μm) Parameters for Prevention of Enamel Erosion. Photomedicine and Laser Surgery. 2012;30(6):331-338. doi:https://doi.org/10.1089/pho.2011.3175
Radiological Society of North America. Bone Densitometry (DEXA , DXA). Radiologyinfo.org. Published 2020. https://www.radiologyinfo.org/en/info/dexa
CDC. Facts About Nuclear Medicine. Radiation and Your Health. Published February 20, 2024. https://www.cdc.gov/radiation-health/data-research/facts-stats/nuclear-medicine.html
MedlinePlus. Bone pain or tenderness: MedlinePlus Medical Encyclopedia. medlineplus.gov. Published 2025. https://medlineplus.gov/ency/article/003180.htm
Whitney E, Alastra AJ. Vertebral Fracture. PubMed. Published April 3, 2023. https://www.ncbi.nlm.nih.gov/books/NBK547673/
Johns Hopkins Medicine. Osteoporosis: What You Need to Know as You Age. www.hopkinsmedicine.org. https://www.hopkinsmedicine.org/health/conditions-and-diseases/osteoporosis/osteoporosis-what-you-need-to-know-as-you-age
Mayo Clinic. Bone cancer – Symptoms and causes. Mayo Clinic. Published 2018. https://www.mayoclinic.org/diseases-conditions/bone-cancer/symptoms-causes/syc-20350217