Who should get a bone density test? Understanding DEXA screening

Osteoporosis is a progressive condition that weakens bones, making them fragile and more susceptible to fractures. Often called a silent disease, it can develop without noticeable symptoms until a fracture occurs. A bone density test can help identify individuals at risk before serious complications arise. Understanding who should undergo screening, when it is recommended, and how the results are interpreted is an important step towards protecting bone health, particularly with advancing age.

What is a DEXA scan and why is it important?

Dual-energy X-ray absorptiometry (DEXA or DXA) is a widely used, non-invasive test to measure bone mineral density (BMD). It commonly examines the hip and lumbar spine, where bone loss can increase the risk of fractures. The procedure uses a low dose of radiation and is generally quick and painless. The test helps identify osteoporosis, assess the likelihood of fractures and monitor bone health over time, including the response to treatment. Unlike investigations performed after a fracture, DEXA can detect low bone density before a major injury occurs, allowing preventive measures or treatment to be considered.

Who should get a bone density test?

Bone density screening is particularly important for individuals with an increased risk of bone loss. Women aged 65 and above and men aged 70 and above should discuss screening with their healthcare providers.

Postmenopausal women younger than 65 and men aged 50–69 may also require testing if they have additional risk factors. Screening may be recommended earlier for individuals who have experienced a fracture following a minor fall or injury, have a family history of osteoporosis or hip fractures, or have medical conditions associated with reduced bone density. These include certain hormonal disorders, malabsorption conditions and chronic inflammatory diseases. People taking corticosteroids over an extended period may also be at increased risk. Other contributing factors include low body weight, smoking, excessive alcohol consumption, and a history of significant height loss or vertebral fractures. The decision to undergo testing should be based on age, medical history, individual risk factors, and clinical assessment.

How are DEXA results interpreted?

DEXA results are commonly reported as a T-score, which compares bone density with that of a healthy young adult.

• Normal bone density: T-score of −1.0 or above.
• Low bone mass (osteopenia): T-score between −1.0 and −2.5.
• Osteoporosis: T-score of −2.5 or below.

These thresholds are primarily used to classify bone density in postmenopausal women and men aged 50 and older. In younger individuals, Z-scores and clinical context may be more appropriate. A low bone density result does not automatically mean a fracture is imminent; healthcare professionals also consider age, previous fractures, and other clinical factors when assessing risk.

Can osteoporosis be prevented?

While age-related bone loss cannot always be avoided, several measures can help maintain bone strength. Adequate calcium and vitamin D intake, regular weight-bearing and muscle-strengthening exercises, avoiding smoking, limiting alcohol, and taking precautions to prevent falls are important. Individuals diagnosed with osteoporosis or at high risk of fractures may require medication alongside lifestyle changes. Follow-up assessments should be guided by the treating clinician, depending on baseline bone density, treatment, and individual risk.

When should you consult a doctor?

Persistent back pain, unexplained height loss, a stooped posture, or a fracture following a minor fall should prompt medical evaluation. These signs do not always indicate osteoporosis, but they may warrant further investigation.

Bone density testing is not necessary for everyone, but timely DEXA screening can help identify those at risk, support informed treatment decisions, and reduce the likelihood of preventable fractures. Understanding individual risk and seeking medical advice at the right time are essential to maintaining bone health and independence with age.

The author is the chief of lab, Metropolis Healthcare Ltd. (Kerala). 

 

The opinions expressed in this article are those of the author and do not purport to reflect the opinions or views of THE WEEK.