When we talk about bone health, the first thing that comes to mind is calcium. But as any bone specialist will tell you, calcium is just one part of a much bigger picture. To really understand what’s going on inside your bones—and to treat bone loss effectively—doctors rely on something far more precise: a DEXA scan.
What is a DEXA scan—and why is it so important?
A DEXA scan (short for Dual-Energy X-ray Absorptiometry) is a simple, non-invasive test that helps assess bone mineral density (BMD). It gives doctors a real sense of how strong or fragile your bones are, allowing them to move beyond guesswork and offer treatment that’s actually suited to your needs.
Unlike a regular X-ray, a DEXA scan uses two low-dose beams to measure the density of bones—most commonly in the spine, hip, and sometimes the forearm. It doesn’t take long, and there’s no prep required. But the insights it offers are deep.
The numbers that matter: T-scores and Z-scores
For your daily dose of medical news and updates, visit: HEALTH
Once the scan is done, you’ll get two important numbers: the T-score and the Z-score.
* T-score compares your bone density to that of a healthy young adult. It helps diagnose conditions like osteoporosis or osteopenia (mild bone loss).
* Z-score compares your bone density to someone your age. This is especially useful when doctors are looking for secondary causes of bone loss—things like hormone imbalances or less common conditions that might be weakening your bones.
Not all bone loss is the same—so treatment shouldn’t be either
Depending on where your numbers fall, you could be told your bones are normal, mildly weakened (osteopenic), or severely weak (osteoporotic). What’s helpful is that this isn’t just a label—it’s a starting point for a tailored treatment plan.
That plan might include oral or injectable medications, calcium and vitamin D, exercise, dietary tweaks, or, in some cases, hormone therapy. The key is that it’s not a blanket recommendation. It’s specific to what your bones need.
Looking deeper when things don’t add up
One of the underappreciated strengths of the DEXA scan is how it helps doctors spot red flags for secondary bone loss. Sometimes, a low T-score isn’t just about ageing or nutrition—it could point to more serious issues, like a rare bone sarcoma that weakens a particular area. These cases need completely different treatment paths, and a timely DEXA scan can make all the difference in catching them early.
Tracking how your bones respond to treatment
Another advantage of DEXA? It helps track progress. If you’re on medication—like bisphosphonates or bone-building drugs—doctors can compare your current scan with the last one to see if the treatment is working. If it’s not, adjustments can be made early rather than waiting for a fracture to happen.
Bonus benefit: It checks muscle and fat, too
Not many people know this, but DEXA can also measure body composition—that includes fat and muscle mass. This is especially helpful if you’re dealing with obesity or muscle loss, both of which increase the risk of falls and fractures. Knowing this information allows doctors to make more rounded decisions about your overall musculoskeletal health, not just your bones in isolation.
In short: It’s not just about calcium anymore
If you’ve been told to “just take calcium” for your bone health, it might be time to dig deeper. A DEXA scan offers a full picture—not just of where your bone health stands today, but where it’s headed. It helps doctors shift from generic advice to smart, specific care that actually works. Bone health is personal. Your treatment plan should be too.
Dr Samarth Arya, Consultant - Orthopaedics & Robotic Joint Replacement Surgery, Manipal Hospital, Old Airport Road
The opinions expressed in this article are those of the author and do not purport to reflect the opinions or views of THE WEEK.
