A DEXA scan report boils down to a handful of numbers, and the most important one is your T-score. If your T-score is minus 1.0 or higher, your bone density is considered normal. A score between minus 1.0 and minus 2.5 means you have osteopenia, or low bone mass. A score of minus 2.5 or lower means osteoporosis. That single number, measured in standard deviations from the bone density of a healthy 30-year-old, is what your doctor uses to assess your fracture risk and decide whether treatment is warranted. For example, a 68-year-old woman whose DEXA report shows a femoral neck T-score of minus 1.8 falls into the osteopenia range, meaning her bones have thinned but she has not yet crossed the threshold into osteoporosis. But a DEXA report contains more than just the T-score.
You will also see a Z-score, which compares your bones to people your own age rather than to a 30-year-old. You may find a FRAX score estimating your 10-year fracture probability. And the report will list results for multiple skeletal sites, each telling a slightly different story about your bone health. This article walks through every section of a typical DEXA scan report, explains what the numbers mean in plain language, covers who should get screened and how often, and addresses the connection between bone health and cognitive decline that makes this topic particularly relevant for anyone concerned about aging and dementia risk. Understanding your DEXA results matters more than most people realize. An estimated 10 million Americans over age 50 have osteoporosis, and another 43 million have low bone mass. Hip fractures in older adults are strongly associated with accelerated cognitive decline, loss of independence, and increased mortality. Reading your own report rather than waiting for a brief phone call summary puts you in a better position to ask the right questions and advocate for your care.
Table of Contents
- What Do the Numbers on a DEXA Scan Report Actually Mean?
- Which Skeletal Sites Are Measured and Why the Location Matters
- Understanding FRAX Scores and Your 10-Year Fracture Risk
- Who Should Get a DEXA Scan and How Often Should You Repeat It?
- Common Pitfalls When Reading Your Own DEXA Report
- The Connection Between Bone Health and Brain Health
- What to Expect as Screening and Treatment Evolve
- Conclusion
- Frequently Asked Questions
What Do the Numbers on a DEXA Scan Report Actually Mean?
dexa stands for Dual-Energy X-ray Absorptiometry, and it is the gold standard recognized by the World Health Organization for measuring bone mineral density. The scan works by passing two low-dose X-ray beams through your bones at different energy levels. The machine then calculates your bone mineral density in grams per centimeter squared. That raw BMD number appears on your report, but it is not particularly useful on its own because bone density varies widely by skeletal site, age, sex, and ethnicity. That is why the report converts your raw BMD into standardized scores. The T-score is the primary diagnostic number. It tells you how many standard deviations your bone density falls above or below the average peak bone mass of a healthy 30-year-old adult. A T-score of zero means your bones are exactly average for a young adult at peak density. Every full point below zero represents a meaningful increase in fracture risk.
According to Johns Hopkins Medicine, fracture risk roughly doubles with every one standard deviation decrease. So a person with a T-score of minus 2 has approximately four times the fracture risk of someone at zero. The Z-score, by contrast, compares you to people your own age, sex, ethnicity, and body size. If your Z-score is minus 2.0 or lower, it is considered below the expected range for your age and signals that something beyond normal aging may be driving your bone loss, such as a medication side effect, a hormonal disorder, or a nutritional deficiency. To put this in concrete terms, imagine two women who are both 72 years old. One has a lumbar spine T-score of minus 1.4 and a Z-score of minus 0.3. Her bones are thinner than a young adult’s, but they are about average for her age. The other has a T-score of minus 2.7 and a Z-score of minus 2.2. Not only does she have osteoporosis by the WHO classification, but her bones are significantly worse than expected even for a woman in her early seventies. That Z-score gap should prompt her doctor to look for an underlying cause beyond normal aging.
Which Skeletal Sites Are Measured and Why the Location Matters
Your DEXA report will list results for several body regions, and not all of them carry equal diagnostic weight. The standard sites are the lumbar spine covering vertebrae L1 through L4, the femoral neck which is a specific region of the upper hip bone, and the total hip which includes the femoral neck plus the trochanter and Ward’s region. Some reports also include the 33 percent radius, a spot on the forearm near the wrist, though this is typically reserved for cases where the hip or spine cannot be reliably measured, such as in patients with bilateral hip replacements or severe spinal arthritis. Here is a detail that catches many patients off guard: you can have normal bone density at one site and osteoporosis at another. Spinal arthritis and degenerative disc disease, both common in older adults, can actually inflate lumbar spine BMD readings because the extra calcification from bone spurs gets picked up by the scanner. A 74-year-old man might see a reassuringly normal spine T-score of minus 0.5 while his femoral neck comes back at minus 2.6.
If he only looked at the spine number, he would miss a diagnosis of hip osteoporosis. This is why the WHO classification uses the lowest T-score among all measured sites for the official diagnosis. Your doctor should be looking at the worst number, not the best one. However, if you are under 50, premenopausal, or male under age 50, the diagnostic rules change. In these populations, the Z-score rather than the T-score is the primary metric. The International Society for Clinical Densitometry recommends against using the WHO T-score categories for younger patients because comparing a 35-year-old’s bones to a 30-year-old’s peak is not clinically meaningful in the same way. If your report was generated without accounting for your age and sex, it is worth asking your doctor whether the correct reference population was used.
Understanding FRAX Scores and Your 10-Year Fracture Risk
Many DEXA reports now include a FRAX score, which stands for Fracture risk Assessment Tool. While the T-score tells you how dense your bones are right now, the FRAX score estimates the probability that you will actually break a bone in the next 10 years. It combines your femoral neck BMD with clinical risk factors including your age, sex, body mass index, history of prior fractures, parental history of hip fracture, smoking status, alcohol use, glucocorticoid use, and whether you have rheumatoid arthritis or other conditions linked to secondary osteoporosis. The FRAX calculation produces two numbers: your 10-year probability of a major osteoporotic fracture at any of four sites, being the spine, hip, forearm, or humerus, and your 10-year probability of a hip fracture specifically. In the United States, treatment is generally recommended when the 10-year major fracture risk exceeds 20 percent or the 10-year hip fracture risk exceeds 3 percent.
For example, a 70-year-old woman with a femoral neck T-score of minus 2.0, a prior wrist fracture, and a mother who broke her hip might have a FRAX-estimated major fracture risk of 25 percent, well above the treatment threshold, even though her T-score alone only qualifies as osteopenia rather than osteoporosis. This matters enormously for dementia caregivers. A person with cognitive impairment is already at higher risk for falls due to balance problems, medication side effects, and spatial disorientation. If their FRAX score indicates elevated fracture risk on top of that fall risk, the combination can be devastating. Hip fractures in people with dementia carry mortality rates roughly double those of cognitively intact patients, and survivors frequently experience a sharp, permanent decline in function and cognition. Knowing the FRAX score can help families and care teams prioritize fall prevention strategies alongside bone-strengthening treatments.
Who Should Get a DEXA Scan and How Often Should You Repeat It?
The U.S. Preventive Services Task Force recommends bone density screening for all women over age 65 and for younger postmenopausal women who have risk factors such as low body weight, previous fractures, family history of osteoporosis, smoking, or long-term steroid use. There is no universal screening recommendation for men, though many guidelines suggest testing men over 70 or younger men with significant risk factors. If you are caring for someone with dementia, it is worth asking their doctor about screening even if it has not been brought up, because the consequences of a fracture in that population are so severe. The timing of repeat scans involves a tradeoff between catching bone loss early and avoiding unnecessary testing. Medicare Part B covers a DEXA scan once every two years, and most clinical guidelines agree that scanning more frequently than every two years is not useful for the general population because bone density changes slowly enough that the measurement error of the machine can obscure real changes over shorter intervals.
However, patients who have just started osteoporosis medication such as a bisphosphonate or denosumab may get annual scans to confirm the treatment is working. If you are paying out of pocket, costs range from roughly 40 to 400 dollars depending on the facility and location, though some facilities without insurance negotiated rates charge up to 1,130 dollars. It is worth calling ahead to compare pricing, as costs vary enormously even within the same city. One practical consideration: for the most accurate comparison over time, you should try to get your repeat scan on the same machine at the same facility. Different DEXA machines from different manufacturers can produce slightly different BMD values, and switching machines between scans can create the illusion of bone loss or gain that is really just measurement variation. If you have changed providers, bring your prior scan results so the radiologist can note the machine difference in their interpretation.
Common Pitfalls When Reading Your Own DEXA Report
The most frequent mistake patients make is looking only at the T-score and ignoring context. A T-score of minus 1.2 might sound mildly concerning, but for an 82-year-old it could actually represent better-than-average bone density for her age, reflected in a Z-score well above zero. Conversely, a T-score of minus 1.8 in a 55-year-old is more alarming because she has decades ahead of her during which bones will continue to thin and fracture risk will compound. Another common source of confusion is comparing T-scores between different body sites as if they are on the same scale. A T-score of minus 2.0 at the lumbar spine does not mean the same thing as minus 2.0 at the femoral neck in terms of absolute fracture risk. Hip fractures are generally more dangerous and disabling than vertebral compression fractures, though spinal fractures can cause chronic pain, loss of height, and kyphosis that impairs breathing.
Some patients also misread their report by confusing the T-score and Z-score columns, especially when the report layout is dense. The T-score is always the one compared to a young adult reference, and the Z-score is always the age-matched comparison. Be cautious about interpreting small changes between sequential scans as meaningful. DEXA machines have a precision error typically around 1 to 2 percent for the spine and 1.5 to 2.5 percent for the hip. A change in BMD needs to exceed what is called the least significant change, usually around 3 to 5 percent depending on the site, before you can be confident the change is real and not just measurement noise. If your doctor says your bone density dropped by 1.5 percent over two years, that may or may not represent actual bone loss. Ask whether the change exceeds the least significant change threshold for the machine used.
The Connection Between Bone Health and Brain Health
Research increasingly shows that osteoporosis and dementia share common risk factors and may even share biological pathways. Both conditions are associated with chronic inflammation, vitamin D deficiency, reduced physical activity, and hormonal changes after menopause. Several large epidemiological studies have found that people with lower bone density have a higher incidence of cognitive decline and dementia, though the relationship is complex and not necessarily causal in a direct sense.
What is clearly causal is the devastating chain of events that a fracture can set in motion for someone with cognitive impairment. A hip fracture often means surgery, hospitalization, immobility, delirium, and a rehabilitation process that a person with dementia may not be able to fully participate in. For caregivers and families, understanding bone density results is part of a broader strategy to reduce catastrophic health events. If your loved one’s DEXA scan shows osteopenia or osteoporosis, that result should inform decisions about home safety modifications, exercise programs, calcium and vitamin D supplementation, and whether pharmacological treatment for bone loss makes sense given the person’s overall health and goals of care.
What to Expect as Screening and Treatment Evolve
Osteoporosis prevalence in the United States is projected to increase by over 30 percent by 2030 as the population ages. This growing burden has prompted interest in broader screening programs, more accessible DEXA scanning, and newer treatments that build bone rather than merely slowing its loss. Anabolic agents like romosozumab and teriparatide represent a shift from the older bisphosphonate approach, though they come with higher costs and specific usage windows.
For the dementia care community, the future likely holds greater integration of bone health screening into cognitive care plans. As geriatric medicine moves toward more comprehensive assessments of fall risk, frailty, and functional capacity, the DEXA scan may become a routine part of the workup alongside cognitive testing. In the meantime, anyone over 65, and especially anyone caring for a person with dementia, should consider bone density results as a critical piece of the overall health picture rather than an isolated number on a report.
Conclusion
Reading a DEXA scan report comes down to understanding a few key numbers and knowing which one matters most for your situation. The T-score is the primary diagnostic tool for postmenopausal women and men over 50, with scores of minus 1.0 or higher considered normal, minus 1.0 to minus 2.5 indicating osteopenia, and minus 2.5 or lower signaling osteoporosis. The Z-score tells you how your bones compare to others your age. The FRAX score, when included, estimates your actual 10-year fracture probability by combining bone density data with clinical risk factors. The lowest T-score among all tested sites determines the diagnosis.
The practical next step after receiving your results is straightforward. If your scores are normal, continue weight-bearing exercise, adequate calcium and vitamin D intake, and rescreen at the interval your doctor recommends. If you have osteopenia, discuss your FRAX score to determine whether lifestyle measures alone are sufficient or whether medication should be considered. If you have osteoporosis, treatment is generally recommended to reduce fracture risk. For anyone caring for a loved one with cognitive decline, a DEXA scan is a small investment that can inform major decisions about safety and care planning. With lifetime fracture risk reaching 46.4 percent for women and 22.4 percent for men, bone health deserves at least as much attention as blood pressure or cholesterol.
Frequently Asked Questions
What is the difference between a T-score and a Z-score on a DEXA scan?
The T-score compares your bone density to a healthy 30-year-old at peak bone mass and is the primary diagnostic score for postmenopausal women and men over 50. The Z-score compares you to people of your same age, sex, ethnicity, and body size. A Z-score of minus 2.0 or lower suggests bone loss beyond what is expected for your age and may indicate an underlying condition.
How often should I get a DEXA scan?
Medicare covers a DEXA scan once every two years, and most guidelines agree that scanning more frequently than every two years is unnecessary for routine monitoring. Patients on osteoporosis treatment may get annual scans to assess whether the medication is working. Always try to use the same machine for follow-up scans to ensure accurate comparisons.
Does osteoporosis affect dementia risk?
Osteoporosis and dementia share many risk factors including inflammation, vitamin D deficiency, and physical inactivity. While low bone density does not directly cause dementia, a fracture resulting from osteoporosis, especially a hip fracture, can trigger hospitalization, delirium, and rapid cognitive decline in people who already have cognitive impairment.
How much does a DEXA scan cost without insurance?
Out-of-pocket costs in 2026 range from about 40 to 400 dollars depending on the facility and location, with some facilities charging up to 1,130 dollars without insurance. Many imaging centers offer self-pay discounts, so it is worth calling to compare prices. Medicare Part B covers the scan for eligible patients.
At what T-score should I start treatment for osteoporosis?
Treatment is typically recommended for a T-score of minus 2.5 or lower, which qualifies as osteoporosis. However, treatment may also be recommended for osteopenia if your FRAX score shows a 10-year major fracture risk above 20 percent or a hip fracture risk above 3 percent. Your doctor will weigh your overall risk profile including age, fall history, and other health conditions.
Can bone density improve after a low DEXA score?
Yes, but improvements are usually modest. Weight-bearing exercise, adequate calcium and vitamin D, and osteoporosis medications such as bisphosphonates or anabolic agents can stabilize or modestly increase bone density over time. However, a change in BMD needs to exceed about 3 to 5 percent to be considered real rather than measurement variation, so do not be discouraged if early repeat scans show small or no gains.
