DEXA Scans in Menopause: Timing, T-Scores, and What to Do With the Result

A DEXA scan — dual-energy X-ray absorptiometry — measures how much mineral is packed into your bones. It passes two X-ray beams of different energies through the body and calculates density from how much each is absorbed.

The radiation dose is genuinely small: comparable to a few hours of ordinary background radiation, and a small fraction of a chest X-ray. The scan takes ten to twenty minutes, you stay fully clothed (minus metal), and nothing goes into your body. There's no injection, no contrast, and no recovery time.

Standard scans measure two sites: the lumbar spine (L1 through L4) and the proximal femur (hip). Sometimes the forearm is added — typically when the spine or hip can't be measured reliably, or in people with hyperparathyroidism. The spine and hip are chosen because they're where osteoporotic fractures do the most damage, and because they respond differently to hormone loss.

What DEXA does *not* tell you is bone quality — the microarchitecture and collagen structure that also determine whether a bone breaks. Two women with identical T-scores can have meaningfully different fracture risk, which is one reason clinicians don't treat the number in isolation.

Some centers also offer a VFA (vertebral fracture assessment) with the same machine, a lateral spine image that detects compression fractures you may not know you have. Around two-thirds of vertebral fractures are silent — no dramatic moment, just a gradual loss of height. If you've lost more than an inch and a half of height, ask whether VFA can be added. A previously unrecognized vertebral fracture changes management significantly, often more than the T-score does. We cover the broader picture in [osteoporosis prevention in menopause](/blog/osteoporosis-prevention-in-menopause-protecting-bone-after-45).

Your T-score compares your bone density to that of a healthy young adult at peak bone mass, expressed in standard deviations. It is the number that defines diagnosis.

• •Above -1.0: normal
• •-1.0 to -2.5: osteopenia, sometimes called low bone mass
• •-2.5 or below: osteoporosis
• •-2.5 or below plus a fragility fracture: severe or established osteoporosis

Each full point represents roughly a 10-12% difference in density, and fracture risk approximately doubles for every standard deviation drop. So a T-score of -2.0 doesn't mean you're "a bit below average" — it means your fracture risk is several times that of someone at -0.5.

Your Z-score compares you to people of your own age and sex. In postmenopausal women it's less central to diagnosis, but a Z-score below -2.0 is a flag that something beyond normal aging may be at work — celiac disease, hyperparathyroidism, early menopause, long-term steroid use, or an eating disorder history. If your Z-score is low, the right response is investigation, not just calcium.

One wrinkle worth knowing: the diagnosis uses the lowest T-score among the measured sites. If your spine is -1.4 and your hip is -2.6, you have osteoporosis.

Another: spinal arthritis, compression fractures, and aortic calcification all falsely *raise* spine density readings, because the scanner counts any calcium in the beam path. In women over 65 especially, a spine score that looks better than the hip score should be read with caution. A good report will note whether degenerative change may be affecting the result.

The universal recommendation is age 65 for all women. The more useful question is whether you should go earlier — and for many women in menopause, the answer is yes.

The U.S. Preventive Services Task Force recommends bone density screening for women 65 and older, and for postmenopausal women younger than 65 who are at increased risk of osteoporosis. What counts as increased risk:

• •Early menopause — before 45, or surgical menopause at any age
• •A fragility fracture after 40 — a break from a fall at standing height or less
• •Long-term glucocorticoid use — roughly three months or more of oral steroids
• •A parent who fractured a hip
• •Low body weight, typically a BMI under 20, or significant recent weight loss
• •Smoking or regular alcohol intake above two drinks daily
• •Rheumatoid arthritis, celiac disease, inflammatory bowel disease, or hyperparathyroidism
• •Aromatase inhibitors for breast cancer, or androgen deprivation therapy

There's also an argument for a baseline scan in early menopause independent of risk factors. SWAN data show bone loss accelerates dramatically in a narrow window — about a year before the final period through two years after — averaging close to 1.8% per year at the spine. A woman can lose roughly 10% of spinal bone mass across the transition. Knowing where you started makes every future scan interpretable; a single scan at 65 tells you where you are but not how fast you got there.

If you're navigating early menopause specifically, [premature ovarian insufficiency](/blog/premature-ovarian-insufficiency-early-menopause-before-40) carries particular bone implications worth understanding.

FRAX is a free online calculator that estimates your probability of a major osteoporotic fracture — hip, spine, forearm, or shoulder — over the next ten years. It takes your T-score and combines it with clinical risk factors that DEXA can't see.

The inputs: age, sex, weight, height, previous fracture, parental hip fracture, current smoking, glucocorticoid use, rheumatoid arthritis, secondary osteoporosis, alcohol intake, and femoral neck bone density.

Why this matters: two women can both have a T-score of -2.2 — osteopenia, not osteoporosis — and have completely different management. A 52-year-old non-smoker with no fracture history might have a 10-year major fracture probability of 5%. A 68-year-old who smokes, whose mother broke a hip, and who has been on prednisone might come out at 22% with the same T-score. The first woman needs lifestyle measures and a repeat scan. The second meets typical treatment thresholds.

In the U.S., treatment is commonly considered when the 10-year probability of hip fracture reaches 3% or major osteoporotic fracture reaches 20%, alongside a T-score at or below -2.5 or a prior hip or vertebral fracture.

FRAX has limits worth knowing. It doesn't capture fall risk, dose or duration of steroid use, or the number of prior fractures. It can underestimate risk in someone with multiple vertebral fractures. And it isn't validated for women already on treatment. It's a structured starting point for a conversation, not a verdict.

Ask your clinician to run FRAX with you rather than accepting "your scan was fine." Osteopenia covers an enormous range, and where you sit inside it is the thing that matters.

It depends on your result and whether anything is actively changing — and repeating too soon is a common waste.

General intervals used in practice:

• •Normal T-score, no risk factors: every 10-15 years is often sufficient
• •Mild osteopenia (-1.0 to -1.5): roughly every 5 years
• •Moderate to advanced osteopenia (-1.5 to -2.5): every 2-3 years
• •Osteoporosis or on treatment: every 1-2 years
• •Starting or stopping HRT, or on steroids: shorter intervals, individualized

The reason not to scan annually in a stable person is precision. DEXA machines have a measurement error of roughly 1-2%, and typical annual bone change in a stable postmenopausal woman is of the same magnitude. A "decline" over one year is often noise. You need enough time for real change to exceed measurement error — usually two years minimum.

One rule that matters more than the interval: repeat on the same machine whenever possible. Different manufacturers calibrate differently, and comparing a GE scan to a Hologic scan can produce an apparent change that is purely equipment. If you move or change clinics, tell the new center you need a comparison and ask whether they can cross-calibrate.

A situation that justifies an earlier repeat: significant rapid weight loss. Losing weight quickly is associated with bone loss, and for women simultaneously in menopause and on a GLP-1 medication, two bone-density risks stack. That combination is worth raising specifically — we cover it in [GLP-1 and bone density in menopause](/blog/glp1-bone-density-in-menopause-the-double-risk). Starting or stopping hormone therapy is another reasonable trigger, since estrogen has a direct and measurable effect on bone turnover.

First: a low T-score is information, not a sentence. Bone is living tissue that remodels continuously, and both loss and gain are possible.

Step one — look for treatable causes. Especially with a low Z-score, ask about vitamin D level, calcium, kidney and liver function, thyroid and parathyroid function, and celiac screening. Secondary causes are found more often than people expect, and treating the cause changes the trajectory.

Step two — address the load on your skeleton. Bone responds to mechanical stress, and the stimulus that matters is progressive resistance training and impact, not walking alone. Programs like LIFTMOR demonstrated that supervised heavy resistance and impact training improved bone density in postmenopausal women with low bone mass. Two sessions weekly of properly loaded compound movements does more for bone than any amount of light cardio. [Resistance training for bone density](/blog/osteoporosis-prevention-in-menopause-protecting-bone-after-45) covers the specifics.

Step three — get the nutritional inputs right. Adequate calcium (food first, supplements to fill the gap), vitamin D, and — often overlooked — enough protein. Protein is a structural component of bone matrix, and low intake is associated with worse bone outcomes. See [calcium and vitamin D for menopause](/blog/calcium-and-vitamin-d-for-menopause-how-much-you-need) and [protein in menopause](/blog/protein-in-menopause-how-much-to-prevent-muscle-loss).

Step four — discuss medication honestly. For women within ten years of menopause with significant symptoms, hormone therapy preserves bone density and reduces fracture risk. For osteoporosis specifically, bisphosphonates, denosumab, and anabolic agents like teriparatide or romosozumab each have a place. Which one depends on your fracture risk, kidney function, and how urgently density needs to rise.

The worst outcome is a scan that gets filed and forgotten. Ask for your actual T-scores in writing, keep them, and bring them to the next scan.