Diagnosis & Bone Density Testing

A medical evaluation to diagnose osteoporosis and estimate your risk of breaking a bone may involve one or more of the following steps:

  • Medical History
  • Physical examination
  • Bone density test
  • FRAX®score
  • Laboratory tests

Other tests that may be used to get information about your bone health, but are not used to diagnose osteoporosis include biochemical marker tests, x-rays, vertebral fracture assessments (VFAs), and bone scans.

What a Bone Density Test Can Do

A bone density test can help you and your healthcare provider:

  • learn if you have weak bones or osteoporosis before you break a bone
  • predict your chance of breaking a bone in the future
  • see if your bone density is improving, getting worse or staying the same
  • find out how well an osteoporosis medicine is working
  • let you know if you have osteoporosis after you break a bone

Who Should Have a Bone Density Test?

The NOF recommends that you have a bone density test if:

  • you are a woman age 65 or older
  • you are a man age 70 or older
  • you break a bone after age 50
  • you are a woman of menopausal age with risk factors
  • you are a postmenopausal woman under age 65 with risk factors
  • you are a man age 50-69 with risk factors

A bone density test may also be necessary if you have any of the following:

  • an X-ray of your spine showing a break or bone loss in your spine
  • back pain with a possible break in your spine  
  • height loss of ½ inch or more within one year
  • total height loss of 1½ inches from your original height

Understanding Bone Density Test Results

Your bone density test results are reported using T-scores. A T-score shows how much your bone density is higher or lower than the bone density of a healthy 30-year old adult. A healthcare provider looks at the lowest T-score to diagnosis osteoporosis. According to the World Health Organization (WHO):

  • A T-score of -1.0 or above is normal bone density. Examples are 0.9, 0 and -0.9.
  • A T-score between -1.0 and -2.5 means you have low bone density or osteopenia. Examples are T-scores of -1.1, -1.6 and -2.4.
  • A T-score of -2.5 or below is a diagnosis of osteoporosis. Examples are T-scores of -2.6, -3.3 and -3.9.

The lower a person’s T-score, the lower the bone density. A T-score of -1.0 is lower than a T-score of 0.5 and a T-score of -3.5 is lower than a T-score of -3.0.

Healthcare providers measure bone density in the hip and spine for several reasons. First, people with osteoporosis have a greater chance of fracturing these bones. Second, broken bones in the hip and spine can cause more serious problems, including longer recovery time, greater pain and even disability. Bone density in the hip and spine can also predict the likelihood of future breaks in other bones.

FRAX® – The Fracture Risk Assessment Tool

FRAX® is a scientifically validated risk assessment tool, endorsed by the WHO, that uses information about your bone density and other risk factors for breaking a bone to estimate your 10-year fracture risk. Your FRAX® score estimates your chance of breaking a hip as well as your combined chance of breaking a hip or other major bones over the next ten years. Other major bones include the spine, hip, forearm and shoulder.

The FRAX® tool can be used to guide treatment decisions in people who meet the following three conditions:

  • Postmenopausal women or men age 50 and older
  • People with low bone density (osteopenia)
  • People who have not taken an osteoporosis medicine

If you have low bone density (osteopenia), your DEXA report may include your FRAX® score along with your bone density. If it doesn’t, your healthcare provider can find out your FRAX® score using a web-based version.

Visit www.shef.ac.uk/FRAX for more information.