Bone health screening is the process of measuring bone mineral density (BMD) to detect thinning bones before fractures occur. One of the main tools for bone health screening is the DEXA scan (dual-energy x-ray absorptiometry). This is a noninvasive imaging test that sends two low-dose X-ray beams through the hip and spine to measure bone mineral content. It is a bone densitometry test that quantifies how much mineral is packed into your bones. This data is crucial for diagnosing osteoporosis and assessing fracture risk. In many cases, DEXA can act as a preventative bone scan, catching bone weakening early so that lifestyle changes or treatments can be started before fractures happen.
Standard DEXA Scan Eligibility
National guidelines outline clear eligibility criteria for routine bone density testing. The eligibility rules often boil down to a checklist of criteria. Patients who meet one or more of the following criteria should get a DEXA scan:
- Women 65 years of age or older.
- Younger postmenopausal women (50–64) with osteoporosis risk factors.
- Men 70 years of age or older.
- Any adult who has had a fragility fracture.
- People with medical conditions that cause bone loss.
- People taking medications known to weaken bone.
- Lifestyle factors that increase bone loss, such as chronic smoking or heavy alcohol use.
- Women during the menopausal transition with unexplained bone loss or men younger than 70 with strong risk factors.
Bone density testing is strongly recommended for anyone who has had a vertebral fracture on X-ray, lost height quickly, or has multiple risk factors. Meeting any one of these criteria is a red flag to discuss bone density screening with your doctor. Because eligibility criteria vary by insurer and guidelines, it is wise to check coverage.
Beyond Age: Risk Factors and Special Populations
While age and sex are major factors, several other conditions can signal the need for early bone health screening. Bone health screening should be individualized: a younger person may need testing if they have specific risk factors, and an older adult without obvious risk might still be recommended for screening. Key risk factors include hormonal issues, chronic diseases, and medication effects. Doctors commonly note the following as signs you need a DEXA scan:
- Low body weight or malnutrition. People who are very thin or have lost significant weight often have less bone mass to start with.
- Long-term corticosteroid use. Taking steroids like prednisone for months or years can dramatically speed up bone loss.
- Chronic inflammatory diseases. Conditions such as rheumatoid arthritis or lupus not only affect joints but also weaken bones.
- Gastrointestinal malabsorption. Diseases like celiac or Crohn’s can impair calcium and vitamin D uptake, harming bone health.
- Endocrine disorders. Overactive thyroid or parathyroid conditions, diabetes (especially type 1), and other hormone imbalances can affect bone remodeling.
Patients in these categories are often referred for a bone density test before the typical screening age. Anyone with a constellation of risk factors, even if they are in their 50s or 60s, should ask about a DEXA scan.
DEXA for Athletes and Others
One special group of interest is athletes. Although athletes often have stronger bones from exercise, some sports can paradoxically lead to low bone density. Many sports medicine clinics use DEXA for athletes to analyze body composition as part of training and health optimization. In this context, a DXA scan helps track muscle gain and fat loss, but it also incidentally checks bone density.
It’s essential to note that a DXA used for body composition assessment in a wellness setting is typically billed differently than a medically indicated osteoporosis screening. Nevertheless, the information can be valuable: if an athlete’s DXA shows low bone density, that is a reason to take preventive action to protect bones. DEXA can be valuable for non-seniors, too. It remains the gold standard for how to check bone density. Even if you are not an older adult, if you have significant risk factors, like amenorrhea in a female athlete, prolonged steroid use, or connective tissue disease, a DEXA scan is the definitive way to assess bone health. Clinics may call this a body composition or bone health evaluation, but the radiation-based test is the same DXA bone density scan used in osteoporosis care.
The DEXA Bone Density Test Procedure
The DEXA bone density test is one of the most reliable methods for measuring bone health, providing doctors with precise information about mineral density and fracture risk. Unlike more invasive diagnostic tools, this procedure is straightforward, quick, and designed to maximize comfort for patients. By understanding the steps involved, you can arrive prepared, know what to expect, and feel confident that the results will accurately reflect your bone health status.
- Preparation Before the Scan: Prior to the exam, patients are generally advised to avoid calcium supplements for at least 24 hours, as elevated calcium can affect results. Jewelry, belts, or clothing containing metal should be removed since these items can interfere with imaging accuracy. Facilities often provide a gown if needed, but you may be able to remain in light clothing without zippers or fasteners. Simple preparations like these ensure that the scan captures only bone density measurements without outside interference, streamlining the process for both patient and technician.
- Positioning on the Table: Once ready, you will lie on a padded table designed for comfort and stability. Clothing remains on unless it contains metal in the scanned area, in which case you may change into a provided gown. The technologist positions your body carefully depending on the region being scanned, commonly the lower spine and hip. Supports, such as a padded block under the legs for spine imaging, help maintain alignment. This careful positioning ensures that the scanner targets the exact regions where osteoporosis is most likely to appear.
- Imaging Process: During the imaging process of a bone health test, the technology is engineered to capture precise information about your skeletal structure while minimizing discomfort and exposure. The machine uses a dual-energy X-ray beam that passes from beneath the padded table and is received by a detector positioned above. Unlike traditional X-rays, this beam operates at a much lower dose, making it safe for repeated use while still capable of differentiating between bone, fat, and lean tissue. As the mechanical arm glides steadily across the body, the equipment measures the absorption of each X-ray wavelength, creating detailed contrasts that reveal mineral density in targeted regions. For patients undergoing a spine scan, supports may be added under the knees to flatten the lower back and improve image clarity. For hip scans, a special foot brace ensures consistent positioning for accurate comparisons across future sessions. Remaining motionless during this short sequence is critical, as even slight movements can introduce blurred images that distort calculations. In certain moments, the technician may request a short breath-hold, not for safety but for precision, as the stillness helps isolate the bone from surrounding tissues in the captured image. The entire process is silent and smooth, with the arm’s motion unobtrusive, allowing most individuals to remain relaxed throughout.
- Comfort During the Exam: The procedure is designed to be painless and non-invasive, with no needles, injections, or enclosed machines. The open design of modern DEXA scanners reduces anxiety and avoids feelings of claustrophobia. Technologists often provide a cushion or blanket for added comfort during the 10–20 minute test. Patients are encouraged to breathe normally and relax as the machine operates quietly. Because of its simplicity, even those with mobility issues usually find the process manageable without significant physical strain.
- Results and Follow-Up: Once the scan is complete, the data collected is transformed into a detailed report through advanced software that interprets the bone’s ability to absorb X-ray energy. The program compares measurements at key skeletal sites, such as the lumbar spine, hip, or forearm, with established reference ranges. These comparisons generate standardized values, including T-scores, which reflect how your bone density compares with a healthy young adult, and Z-scores, which measure your density relative to peers of your same age, sex, and body type. Some software systems also integrate vertebral assessment imaging, enabling the detection of subtle spinal fractures that may go unnoticed but significantly increase the risk of further breaks. With results often available the same day, patients can receive timely feedback, and physicians can immediately begin planning or adjusting treatments such as dietary recommendations, exercise regimens, or medication protocols tailored to the individual’s profile. Follow-up is a vital part of the DEXA process because bone density changes slowly and must be tracked consistently to reveal meaningful trends. For individuals with stable bone health, repeating the scan every two years provides a reliable picture of whether bone density is being maintained or declining.
With its ability to detect subtle changes in bone strength over time, it remains a trusted tool for both early diagnosis and ongoing monitoring, empowering individuals to take proactive steps in maintaining skeletal health.
Interpreting DEXA Results and Bone Strength
After your DEXA bone density scan, the radiologist or technician will provide a report with your bone density results. These are usually given as T-scores and Z-scores for each site measured. The T-score compares your BMD to the “peak bone mass” of a healthy 20–30 year-old adult of the same sex. The Z-score compares you to others of your age, sex, and ethnicity. The World Health Organization (WHO) established simple cutoffs for interpreting the T-score:
- A T-score ≥ -1.0 is considered normal bone density.
- A T-score between -1.0 and -2.5 is considered low bone density or osteopenia.
- T-score ≤ –2.5 is considered osteoporosis.
A T-score of –2.7 in your spine means your bone density there is 2.7 standard deviations below that of a young healthy adult, which qualifies as osteoporosis. If one site (say hip) is –2.2 (osteopenia) and another (spine) is –2.7, the overall diagnosis is osteoporosis.
These scores directly reflect your bone strength: lower numbers indicate weaker, more fragile bones. Clinicians use the T-score to estimate fracture risk and to decide on treatment. In addition to BMD, some scans report the Trabecular Bone Score (TBS), which assesses the microarchitectural quality of bone from the spine image, a complementary “texture” measure of bone health. Even a “normal” T-score does not guarantee invulnerability. DEXA is one tool; clinical risk calculators (like FRAX) incorporate age, weight, history of fractures, and other factors to refine fracture risk. The DEXA bone density test quantifies how much bone material is present, giving a surrogate measure of bone strength. When BMD is low, treatment can be prescribed to help strengthen bone and improve those scores over time.
Bone Density Test Cost
The price of a DEXA scan varies widely. Without insurance, out-of-pocket costs in the U.S. average about $700–$800 per central scan, though this depends on the facility and region. With typical insurance, your share is much lower, often around $160–$175 for insured patients. Medicare Part B covers bone density scans every 24 months when a doctor certifies medical necessity based on risk. The scan is fully covered, and you owe nothing out-of-pocket as long as the provider accepts Medicare. Medicare Part A may cover a DEXA if you’re hospitalized and need one for your treatment. Private insurance plans generally follow similar rules: preventive bone density tests are covered at no cost for women 65+ and younger high-risk women. Men’s coverage varies, as most insurers follow USPSTF and Medicare guidance and will cover if men have qualifying risk factors. If you are uninsured or if Medicare doesn’t cover your scan, there are sometimes community programs or screening events that offer reduced-cost DEXA. It’s also worth asking your doctor to appeal to insurance with documentation of risk factors if coverage is denied.
Talk with your doctor about a bone strength test with DEXA. Early identification of bone loss can open the door to interventions that improve bone strength and reduce future fracture risk. Bone health screening is a lifetime approach for anyone at risk. By understanding how a bone density test is done and knowing the signs you need a bone loss test, you can take proactive steps to protect your skeletal health.
Sources:
- Centers for Disease Control and Prevention (CDC). Facts About Bone Density (DEXA Scan).
- RadiologyInfo (Radiological Society of North America). Bone Density Scan (DEXA or DXA) radiologyinfo.org.
- U.S. Preventive Services Task Force (USPSTF). Osteoporosis to Prevent Fractures: Screening (Jan 14, 2025).
- Hospital for Special Surgery (HSS). DEXA Bone Density Tests: A Patient’s Guide (updated 2022) hss.edu.
- UC Davis Sports Medicine. DXA Body Composition Analysis health.ucdavis.edu.
- Medical News Today. When does Medicare cover bone density tests? (updated June 16, 2025) medicalnewstoday.com.