Bone Density (DEXA Scan)

What a DEXA scan is

DEXA stands for dual-energy X-ray absorptiometry. It’s a specialized X-ray that measures the mineral content (calcium and other minerals) in bone. The test is quick (10–15 minutes), painless, and exposes you to minimal radiation—less than a regular chest X-ray.

The scan typically covers two sites:

• Hip — measured at the femoral neck (the narrow part where the femur connects to the pelvis).
• Spine — measured at the lumbar spine (low back), usually at L1–L4.

Some scans also include the forearm, but hip and spine are the standard. The more mineral in the bone, the stronger it is and the lower the fracture risk.

Understanding T-score

The DEXA result is reported as a T-score, which compares your bone density to a healthy 30-year-old’s bone density. The score is measured in standard deviations:

• T-score above -1.0: Normal bone density. No intervention needed.
• T-score between -1.0 and -2.5: Osteopenia (low bone mass). Bone is weaker than ideal, but not yet in the osteoporosis range. Lifestyle changes and possibly medication may help.
• T-score below -2.5: Osteoporosis. Bone is significantly weakened, and the risk of fracture is substantially higher. Treatment with medication is usually recommended.

For every 1.0 decrease in T-score, fracture risk roughly doubles.

Who should get screened

Women 65 and older — universal screening recommended by DEXA.

Men 70 and older — universal screening recommended.

Younger women and men with risk factors — even if you’re below age 65, consider screening if you have:

• Family history of osteoporosis or hip fracture.
• Personal history of fracture from minor trauma (a fall from standing height).
• Long-term use of corticosteroids (like for rheumatoid arthritis).
• Endocrine conditions (hyperthyroidism, hypogonadism).
• Chronic kidney disease, liver disease, or malabsorption disorders.
• Smoking, excess alcohol use, or sedentary lifestyle.
• Women who are postmenopausal (especially if recently postmenopausal).

What to do if your bones are weak

Calcium and vitamin D: Ensure adequate intake. Most adults need 1000–1200 mg of calcium daily and 600–800 IU of vitamin D (or more, depending on sun exposure and age). Dairy, leafy greens, and fortified foods are good sources; supplements may be needed.

Weight-bearing exercise: Walking, jogging, dancing, and resistance training stress the bone and stimulate it to build strength. Aim for 30 minutes most days of the week.

Avoid smoking and limit alcohol: Both weaken bone. If you smoke, quitting is one of the best things you can do for your skeleton.

Bisphosphonates: If osteoporosis is diagnosed or if you have osteopenia plus additional fracture risk factors, your physician may recommend a bisphosphonate (like alendronate or risedronate). These medications slow bone loss and can increase bone density over time.

Fall prevention: Even with strong bones, a bad fall can cause fractures. Remove tripping hazards, improve lighting, wear proper footwear, and consider vision and balance screening.

Repeat screening

If your bones are normal, repeat DEXA screening every 10 years. If you have osteopenia, screening every 1–2 years helps track whether bone density is stable or worsening. If you’re on medication for osteoporosis, scanning every 2 years can show whether the drug is working.

The big picture

Osteoporosis is silent—you don’t feel your bones getting weaker. A DEXA scan is your early warning system. Finding low bone density before a fracture happens lets you take steps to strengthen bone and prevent breaks. Fractures from weak bone (especially hip fractures) can be devastating; prevention through screening and treatment is far better than trying to recover from a fracture.

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