Most of us have seen it happen. Someone who looks perfectly fit slips on a wet floor or has a small accident and ends up with a fracture. In many of these cases, the cause is weak bones, and the most common reason for weak bones is osteoporosis. We usually link it with ageing, but it starts building up quietly, long before anyone notices. Often the first sign is a sudden fracture or back pain that won’t go away, and by then a lot of bone may already be lost. That’s why it makes sense to check your bone health even when you feel completely fine.
Our bones are constantly being renewed. Old bone is broken down, and new bone is laid down in its place. In osteoporosis, the breakdown outpaces the rebuilding. Bones turn thinner, less dense and more fragile, and the spine, hip and wrist are the places most likely to break. Because bone loss causes no pain or obvious warning on its own, the disease can go unnoticed for years, which is why it is called a silent disease. Older age, the drop in oestrogen after menopause, too little calcium or vitamin D, long periods of inactivity and a family history of fractures all raise the risk.
So who should get tested? Screening is worth considering as you grow older, or if you have ever broken a bone after only a minor injury. Other things that raise the risk include low body weight, early menopause, long-term steroid use, and certain thyroid, kidney, liver, digestive or hormonal conditions. Smoking and heavy drinking add to it. Knowing whether you need testing, what tests exist, and what ordinary blood work can tell you about your bones helps you catch the problem sooner and act in time.
Several investigations help us judge bone health and find what may be driving bone loss. These include:
- a complete blood count (CBC)
- kidney function tests, mainly serum creatinine and estimated glomerular filtration rate (eGFR), along with liver function tests
- bone minerals: calcium (total and ionised), phosphorus and magnesium
- alkaline phosphatase, which gives an idea of bone metabolism and turnover
- hormones: parathyroid hormone (PTH) and thyroid tests (TSH and free T4)
- vitamin D levels (D2 and D3)
Depending on your history, these results can point to nutritional deficiencies or an underlying medical condition that is affecting your bones. Another important test is the DEXA (dual-energy X-ray absorptiometry) or DXA scan. It uses a low dose of X-rays to measure bone mineral density, usually at the hip and spine. It is quick, painless and widely used to evaluate weak bones and osteoporosis.
There is also a more specialised group of tests called bone turnover markers. They show how your bones are being remodelled and help doctors monitor how well a patient is responding to osteoporosis treatment and whether they are following it. They fall into two groups. Bone formation markers include P1NP (procollagen type 1 N-terminal propeptide), bone-specific alkaline phosphatase and osteocalcin. Bone resorption markers include serum beta-CrossLaps, also called CTX (C-terminal telopeptide of type I collagen), and urinary NTX (N-terminal telopeptide of type I collagen). Resorption is the natural process in which specialised cells break down bone tissue, while formation is the building of new bone. In everyday practice, P1NP and beta-CrossLaps are the two most commonly used.
One thing to keep in mind: normal calcium or vitamin D levels don’t automatically mean your bones are strong, and an abnormal result alone doesn’t confirm osteoporosis. Your doctor reads the results together with your medical history and risk factors to judge your bone health and your chances of a fracture. A DEXA scan measures bone density, while blood tests help uncover the conditions or deficiencies behind the bone loss.
Put together, they show whether your bone density is normal, lower than expected, or in the osteoporosis range, and they guide the next step, whether that is lifestyle changes, preventive measures or treatment.
The bottom line is simple: don’t judge your bones by how you feel, and don’t wait for a fracture to be the first warning. If you have any of the risk factors, talk to your doctor about the right screening and tests so the cause of bone loss can be found. A diet rich in calcium and vitamin D, regular weight-bearing and muscle-strengthening exercise, staying away from smoking, keeping alcohol low and maintaining a healthy weight all help keep your bones strong as you age and lower the chance of fractures.
This year’s theme for World Osteoporosis Day, on 20th October 2026, is “Build, Protect, Strengthen Your Bones for Life.” It reminds us that bone health is a lifelong job: building strong bones early, protecting them through healthy eating and habits, and strengthening them through timely diagnosis, proper treatment and regular follow-up. Looking after your bones early helps you stay mobile and keeps a silent problem from turning into a serious one.
The author is a consultant pathologist at Metropolis Healthcare Ltd. (Mumbai).
The opinions expressed in this article are those of the author and do not purport to reflect the opinions or views of THE WEEK.
