The standard test is a bone density scan, usually a DEXA scan

A DEXA scan (dual-energy X-ray absorptiometry) is the test your doctor will order to measure bone density. It takes pictures of your bones using very low-dose X-rays and compares your bone density to that of a healthy young adult. The scan itself takes 10 to 30 minutes, is painless, and you remain fully clothed.

DEXA scans measure bone density at your hip, spine, and sometimes forearm — the places where fractures are most likely. Your doctor will look at two numbers: your T-score and Z-score. The T-score tells you how your bones compare to a healthy 30-year-old. A T-score of −1.0 or higher is normal. Between −1.0 and −2.5 means low bone density (sometimes called osteopenia). Below −2.5 means osteoporosis. The Z-score compares you to people your own age and sex, which matters if you are younger or if your results seem unusual.

Not everyone needs a DEXA scan. Your doctor will recommend one based on your age, sex, medical history, and risk factors — for instance, if you are a woman over 65, a man over 70, or anyone with a previous fracture or family history of osteoporosis.

Key Takeaways

  • A DEXA scan is a painless X-ray test that measures bone density at your hip, spine, and sometimes forearm.
  • Your T-score compares your bones to a healthy young adult; a score below −2.5 indicates osteoporosis.
  • Your doctor decides whether you need testing based on age, sex, fracture history, and other risk factors — not everyone is screened.
  • Results take a few days to a week, and your doctor will discuss what they mean and whether treatment is needed.

Who should get tested and when

Screening recommendations differ by age and sex. The U.S. Preventive Services Task Force recommends DEXA screening for all women 65 and older, and for postmenopausal women under 65 who have risk factors. For men, screening is recommended at age 70 and older, or for men 50 to 69 with risk factors.

Risk factors that may move your screening earlier include a previous fracture (especially from a minor fall), family history of osteoporosis or hip fracture, long-term use of corticosteroid medications, rheumatoid arthritis, smoking, heavy alcohol use, or low body weight. If you have had a fracture and are not sure whether you have been tested, tell your doctor — a fracture from a minor injury is itself a sign of weak bones.

Your doctor may also recommend repeat testing every one to two years if you have low bone density or are taking medication for osteoporosis, to see whether the treatment is working.

What happens during the scan

You will lie on a padded table while a scanner arm moves slowly over your body. You need to stay still but do not need to hold your breath. Wear comfortable clothing without metal zippers, snaps, or buckles — metal interferes with the image. You can usually wear a hospital gown or remove just your top and belt.

The technician will position you so the scanner can image your hip and spine clearly. Some scans also include your forearm. The whole appointment, including check-in and paperwork, usually takes 30 to 45 minutes. There is no recovery time — you can go back to your normal activities right away.

If you are pregnant or think you might be, tell the clinic before your appointment. DEXA scans use very little radiation, but pregnancy is still a reason to postpone. If you have had a recent CT scan or nuclear medicine test with contrast dye, mention that too, as it can affect scheduling.

Understanding your T-score and what it means

Your T-score is the number your doctor will focus on. It tells you how many standard deviations your bone density is from that of a healthy 30-year-old woman or man. Here is what the ranges mean:

T-score −1.0 or higher: Normal bone density. No treatment needed unless you have other risk factors. T-score between −1.0 and −2.5: Low bone density (osteopenia). Your bones are weaker than normal but not yet in the osteoporosis range. Your doctor may recommend lifestyle changes, calcium and vitamin D, and possibly medication depending on your age and other risks. T-score −2.5 or lower: Osteoporosis. Your bones are significantly weaker and fracture risk is higher. Your doctor will likely discuss medication and other steps to slow bone loss.

The Z-score is less commonly discussed but still matters. It compares you to people your age and sex. A Z-score below −2.0 can mean something other than aging is causing low bone density — for instance, a hormone problem, kidney disease, or a medication side effect. If your Z-score is unusually low, your doctor may order additional tests to find the cause.

Other tests your doctor might order

A DEXA scan is the main test, but your doctor may also order blood work to check calcium, vitamin D, and kidney function. Low vitamin D is common and easy to treat, so many doctors check this before or alongside a DEXA scan. If your results are surprising or your Z-score is very low, your doctor might order additional imaging or blood tests to rule out other conditions affecting bone health.

If you have had a fracture, your doctor may order X-rays of that area to see the break itself, even though X-rays do not measure bone density the way DEXA does. X-rays show the structure of the bone but are less sensitive for detecting early bone loss.

What to do after you get your results

Your doctor will discuss your results with you, usually within a week of the scan. If your bone density is normal, you may not need another scan for several years — your doctor will tell you when to return. If you have low bone density or osteoporosis, your doctor will talk about treatment options, which may include medication, calcium and vitamin D supplements, exercise, and changes to diet or lifestyle.

Ask your doctor for a copy of your scan results and your T-score. Keep this information in your medical records. If you see a different doctor later, having your baseline scan makes it easier to track changes over time. If you start medication, your doctor will likely recommend repeat testing in one to two years to see whether the medication is slowing bone loss.

Frequently Asked Questions

Does a DEXA scan hurt or expose me to a lot of radiation?

No. The scan is painless and uses less radiation than a standard chest X-ray. You lie still on a table while the scanner passes over you. There is no injection, no contrast dye, and no recovery time.

What if my results show osteoporosis but I have never broken a bone?

Many people with osteoporosis never break a bone, especially if they are careful about falls. Your doctor will discuss whether medication is right for you based on your age, other health conditions, and fracture risk — not just your T-score alone.

Can I get tested at an urgent care or walk-in clinic?

DEXA scans are usually done at hospitals, imaging centers, or bone density clinics, not urgent care. Your primary care doctor can order one and refer you to a facility that has the equipment. Some community health centers also offer DEXA scans.

How often do I need to be retested?

If your bone density is normal, you may not need another scan for five to ten years, depending on your age and risk factors. If you have low bone density or are taking medication for osteoporosis, your doctor will usually recommend repeat testing every one to two years.

What if I cannot afford the test?

DEXA scans are usually covered by Medicare if you meet age and risk criteria. Many insurance plans cover them as well. If cost is a concern, ask your doctor's office about the price and whether financial assistance or payment plans are available at the imaging center.