Bone loss is the menopause symptom that has no symptoms. There is no ache that tells you it is happening. Nothing announces it. For a large number of women the first sign is a broken wrist after a slip on a wet floor, or a vertebra that quietly compresses and shows up as an inch of lost height.
That is the entire argument for screening: to find it before it finds you.
The short answer on timing
At 65, everyone. Screening bone density is recommended for all women at 65 regardless of symptoms or risk factors.
Before 65, if you have risk factors. The ones that matter most:
- A broken bone after age 50 from a fall from standing height or less
- Menopause before age 45, or ovaries removed early
- Oral steroids for three months or longer
- Rheumatoid arthritis
- Low body weight, roughly under 127 pounds
- A parent who broke a hip
- Current smoking
- Three or more alcoholic drinks most days
- Certain medications and conditions affecting bone, including some cancer treatments
Immediately, at any age, if you have already fractured from a fall from standing height after 50. That fracture is itself a clinical diagnosis of osteoporosis regardless of what a scan says. It changes what happens next.
Medicare covers screening DEXA every two years when criteria are met, and more often when medically necessary.
What the scan does
Dual-energy X-ray absorptiometry passes two low-energy X-ray beams through bone and measures how much each is absorbed. The difference gives bone mineral density at the lumbar spine and hip.
It takes about ten minutes. You lie on a table, fully dressed, and the arm passes over you. The radiation dose is a small fraction of a chest X-ray.
The result is a T-score, comparing your density to a healthy young adult:
- Minus 1.0 and above — normal
- Between minus 1.0 and minus 2.5 — osteopenia
- Minus 2.5 or below — osteoporosis
That is where most explanations stop, and it is where the useful part starts.
Why the T-score is not the answer
Here is the fact that reframes everything: more fractures happen in women whose scans read as osteopenia than in women whose scans read as osteoporosis.
That sounds like a contradiction. It is not. Osteoporosis carries higher risk per woman, but there are far more women sitting in the osteopenia range. Multiply a moderate risk by a much larger population and you get more total fractures.
Which means that if you treat by T-score alone, you miss most of the fractures you were trying to prevent.
Bone density also does not capture everything about bone strength. The internal architecture of trabecular bone — the lattice inside — thins and loses connections with age, and that weakens bone in ways a density number does not fully reflect.
What FRAX adds
FRAX is a calculator, developed at the University of Sheffield and used internationally, that estimates your probability of a major osteoporotic fracture and of a hip fracture in the next 10 years.
It uses: age, sex, weight, height, previous fracture as an adult, parental hip fracture, current smoking, oral steroid use, rheumatoid arthritis, secondary osteoporosis, alcohol intake of three or more units daily, and — when you have had a scan — femoral neck bone density.
Two things make it useful. First, it works with or without a bone density result, so it can help decide whether you need a scan at all. Second, it translates a score into a probability, which is a far better basis for a decision than a label.
Two women with identical T-scores of minus 2.0 can have very different FRAX results. One is 52, healthy, has never broken a bone. The other is 68, smokes, has taken steroids for asthma, and her mother broke a hip. Same T-score. Different decisions.
What we also count
Some things override the numbers.
A fragility fracture after 50 — a break from a fall from standing height — is a clinical diagnosis of osteoporosis. So is a vertebral compression fracture found on imaging, even one you never knew about.
Vertebral fractures are worth a paragraph of their own because they are so commonly missed. Many produce no memorable pain event. They show up as height loss, or as a new rounding of the upper back, or incidentally on a chest X-ray done for something else. And they matter enormously: having one substantially raises the risk of the next.
Which is why, where it is indicated, we add vertebral fracture assessment — a low-dose image of the spine taken on the same DEXA machine, in the same sitting. It takes a few extra minutes and it changes management often enough to be worth it.
We also measure your height and compare it with your tallest adult height. Losing more than about an inch and a half is a signal worth chasing.
If your scan is abnormal
Not every abnormal scan means medication.
Osteopenia is a wide range, and treatment depends on calculated fracture risk rather than the label. Some women with osteopenia have FRAX scores that warrant treatment. Many do not, and are better served by calcium and vitamin D sufficiency, weight-bearing and resistance exercise, balance work to prevent falls, and a defined date to look again.
If treatment is warranted, there are several options with different routes, durations, and profiles: bisphosphonates by mouth or by annual infusion, denosumab including biosimilars by injection twice a year, romosozumab and teriparatide for very high risk, and hormone therapy where it fits the window.
One thing we make sure you hear at the start rather than years later: what happens when each treatment stops. Denosumab in particular must not simply be discontinued — bone loss and vertebral fracture risk rebound quickly, so a transition plan to another agent is decided before the first dose. Bisphosphonates are reviewed at 3 to 5 years to consider a drug holiday.
The one-sentence version
If you are 65, get the scan. If you are younger and have any of the risk factors above, get the scan now rather than at 65. And if you have already broken a bone from a minor fall after 50, that conversation should have started already.