What is osteoporosis?
Osteoporosis (literally 'porous bones') is a condition where bone density and bone quality decline to the point where fractures become much more likely. Peak bone mass is reached around age 30, after which bone density gradually declines. In women, this decline accelerates sharply after the menopause due to oestrogen loss. Osteoporosis affects an estimated 200 million people worldwide. The most serious consequences are hip fractures (30% of patients die within a year) and vertebral (spine) fractures causing chronic pain and height loss.
DEXA scan T-score interpretation
| T-score | Diagnosis | Fracture risk |
|---|
| > -1.0 | Normal bone density | Low |
| -1.0 to -2.5 | Osteopenia (low bone density) | Increased |
| ≤ -2.5 | Osteoporosis | High |
| ≤ -2.5 with fracture | Severe osteoporosis | Very high |
Blood tests for osteoporosis workup
| Test | What it checks |
|---|
| Calcium | Abnormal calcium can affect bone metabolism |
| Vitamin D (25-OH) | Deficiency is a major treatable cause of bone loss |
| PTH (parathyroid hormone) | High PTH draws calcium from bones |
| Phosphate | Low phosphate impairs bone mineralisation |
| Thyroid (TSH) | Hyperthyroidism accelerates bone loss |
| Oestrogen / testosterone | Sex hormone deficiency drives bone loss |
| Serum protein electrophoresis (SPEP) | Rules out myeloma as cause of bone disease |
| Urine NTX or CTX (bone turnover markers) | Indicates rate of bone breakdown |
Risk factors for osteoporosis
- Female sex and postmenopausal state (oestrogen loss accelerates bone loss)
- Age over 50
- Family history of osteoporosis or hip fracture
- Low body weight (BMI <18.5)
- Long-term corticosteroid use (>3 months) — the most common cause of secondary osteoporosis
- Low calcium and vitamin D intake
- Smoking and excess alcohol
- Rheumatoid arthritis, inflammatory bowel disease, coeliac disease
- Premature menopause (<45 years)
- Previous fragility fracture
Treatment and prevention
| Intervention | Evidence |
|---|
| Calcium (1,000–1,200 mg/day from diet + supplements) | Foundation of bone health |
| Vitamin D (800–1,000 IU/day; higher if deficient) | Essential for calcium absorption |
| Weight-bearing exercise + resistance training | Stimulates bone formation |
| Bisphosphonates (alendronate, risedronate) | First-line medication; reduces fracture risk by 30–50% |
| Denosumab (injection every 6 months) | Reduces bone resorption; used if bisphosphonates not tolerated |
| HRT (hormone replacement therapy) | For postmenopausal women — discuss risks/benefits with doctor |
Questions to ask your doctor
- Should I have a DEXA scan?
- What is my FRAX fracture risk score?
- Do I need vitamin D and calcium supplementation?
- Should I start bisphosphonate treatment?
- How do I safely take bisphosphonates (fasting, staying upright)?
Medical Disclaimer: This page is for general educational purposes only and does not constitute medical advice. Always consult a qualified doctor for diagnosis and treatment.