Blood work for bone density: what it shows

A bone-density scan measures mineral content in bones, while blood work looks for contributors to bone loss or fracture risk. Depending on your history, a clinician may consider calcium, phosphate, vitamin D, kidney function, thyroid-related markers, blood counts, and tests for inflammation or absorption problems. Results can support assessment of coeliac disease, Crohn's disease, chronic kidney disease, or anaemia when those conditions are relevant. A result outside the usual range is not a diagnosis by itself; it must be interpreted with symptoms, medicines, diet, menstrual or menopause history, and scan findings.

Ask which tests are planned and whether fasting is needed; preparation varies by test and laboratory. Bring a list of prescription medicines, supplements, digestive symptoms, previous fractures, and relevant family history. Do not stop calcium, vitamin D, steroids, or other medicines without advice. If a scan has also been arranged, ask how the blood results will change the next step. Follow-up may involve correcting a deficiency, treating an underlying condition, reviewing medicines, or arranging repeat testing.

Contact a clinician promptly for a new unexplained fracture, severe bone or back pain, marked muscle weakness, confusion, or symptoms of high or low calcium such as unusual thirst, frequent urination, tingling, or spasms. Seek urgent care after a fall if you cannot bear weight, have severe pain, or notice a deformity. Blood-test results should be reviewed with the ordering clinician rather than interpreted alone.

Ask which bone-health causes are being checked, whether you need a density scan, when results will be ready, and whether any medicine or supplement affects interpretation. Ask what result would prompt treatment, dietary advice, or a further test.