Osteoporosis, Bone Density, and Fracture Risk Explained: DXA Scores, Risk Factors, Risk Reduction, and When to Seek Help

Educational disclaimer: This article provides general health education based on published clinical guidelines and research. It is not medical advice and cannot diagnose, prescribe, or replace a consultation with a qualified clinician. Do not start, stop, or change any medication based on this article. If you have concerns about bone health or fracture risk, speak with your doctor.

Common fracture sites in osteoporosis: hip, spine (vertebral compression), and wrist. These fragility fractures can occur from minimal trauma such as a fall from standing height.

What Osteoporosis Means

Osteoporosis is a systemic skeletal condition characterised by low bone mass and deterioration of bone tissue, leading to increased bone fragility and susceptibility to fracture.

Key points:

• Osteoporosis is often called a "silent disease" because bone loss occurs without symptoms until a fracture happens.
• Approximately 200 million people worldwide are affected. One in three women and one in five men over age 50 will experience an osteoporotic fracture.
• It is not a normal or inevitable part of ageing, though age is a major risk factor.
• Fractures from osteoporosis — particularly hip and vertebral fractures — are associated with significant disability, loss of independence, and increased mortality.

How Bone Density Is Measured

Bone mineral density (BMD) is measured using a test called DXA (dual-energy X-ray absorptiometry). It is the gold standard for diagnosing osteoporosis.

Understanding DXA Results

• T-score: Compares your bone density to that of a healthy young adult of the same sex. This is the primary diagnostic measure.
• T-score of −1.0 or above: Normal bone density.
• T-score between −1.0 and −2.5: Osteopenia (low bone mass) — bone density is below normal but not yet osteoporosis.
• T-score of −2.5 or below: Osteoporosis.
• Z-score: Compares your bone density to others of the same age and sex. Used primarily in premenopausal women, men under 50, and children.

Where DXA Measures

Standard DXA scans measure the lumbar spine (L1–L4) and hip (femoral neck and total hip). The lowest T-score at any measured site determines the diagnosis.

Limitations

• DXA measures density (quantity) but not bone quality, microarchitecture, or turnover rate.
• A normal DXA does not guarantee zero fracture risk — other factors (fall risk, bone quality, medications) also matter.
• Peripheral devices (heel ultrasound, finger DXA) are screening tools only and cannot diagnose osteoporosis.
• Consumer wearables and smartwatches cannot measure bone density.

Why Osteoporosis Can Cause Harm

The primary consequence of osteoporosis is fragility fracture — a fracture that occurs from a fall from standing height or less, or from minimal trauma that would not fracture healthy bone.

Common Fracture Sites

• Hip fractures: Most serious. Associated with 20–30% mortality within one year in older adults. Many survivors lose independence permanently.
• Vertebral (spinal) fractures: Often occur without a recognised fall. Can cause chronic back pain, height loss, kyphosis (stooped posture), and reduced lung capacity. Two-thirds are clinically unrecognised.
• Wrist fractures (distal radius): Often the first fragility fracture, typically from a fall onto an outstretched hand. A signal to assess bone health.
• Other sites: Pelvis, humerus (upper arm), ribs.

The Fracture Cascade

Having one fragility fracture approximately doubles the risk of a subsequent fracture. This is sometimes called the "fracture cascade" — early identification and treatment after a first fracture is important for reducing future fracture risk.

Who Is At Higher Risk

Non-Modifiable Risk Factors

• Age — bone density naturally declines after peak bone mass (reached around age 25–30). Risk increases significantly after 50.
• Sex — women are at higher risk due to lower peak bone mass and accelerated bone loss after menopause (oestrogen withdrawal).
• Family history — a parent with a hip fracture approximately doubles your hip fracture risk.
• Ethnicity — Caucasian and Asian populations have higher rates, though osteoporosis affects all ethnic groups.
• Body frame — smaller-framed individuals tend to have less bone mass to draw from as they age.
• Early menopause or hypogonadism — menopause before age 45 (natural or surgical) significantly increases risk due to prolonged oestrogen deficiency.

Modifiable Risk Factors

• Low calcium and vitamin D intake — inadequate nutrition for bone maintenance.
• Physical inactivity — lack of weight-bearing and resistance exercise reduces bone-forming stimulus.
• Smoking — associated with lower bone density and increased fracture risk.
• Excessive alcohol (>3 units/day) — impairs bone formation and increases fall risk.
• Low body weight (BMI <20) — associated with lower bone density and less cushioning in falls.
• Prolonged corticosteroid use — long-term systemic glucocorticoids are a major secondary cause of osteoporosis.

Secondary Causes

Some medical conditions and medications increase osteoporosis risk:

• Rheumatoid arthritis, coeliac disease, inflammatory bowel disease
• Hyperthyroidism, hyperparathyroidism, Cushing syndrome
• Type 1 diabetes, chronic kidney disease
• Aromatase inhibitors (breast cancer), androgen deprivation therapy (prostate cancer)
• Anticonvulsants, proton pump inhibitors (long-term)

What Usually Helps Reduce Risk

No single intervention guarantees fracture avoidance. However, the following risk-reduction themes are supported by guidelines from NICE, NOF, USPSTF, and WHO:

Nutrition

• Calcium: Dietary adequacy matters for bone maintenance. Food sources include dairy, fortified foods, leafy greens, and calcium-set tofu. If intake seems low, discuss assessment and options with a clinician.
• Vitamin D: Supports calcium absorption. Deficiency risk varies by age, sun exposure, diet, skin coverage, and health conditions. Blood levels can be checked if deficiency is suspected.
• Protein: Adequate protein intake supports muscle mass and bone health, particularly in older adults.

Exercise

• Weight-bearing exercise (walking, jogging, dancing, stair climbing) — stimulates bone formation.
• Resistance training (weights, resistance bands) — strengthens muscles and bones at loaded sites.
• Balance and functional training (tai chi, yoga, single-leg stands) — reduces fall risk, which is critical for fracture prevention.

Exercise benefits both bone density and fall prevention. Even in people with established osteoporosis, appropriate exercise is recommended — though high-impact activities may need modification.

Fall Prevention

• Home safety: remove trip hazards, improve lighting, install grab rails in bathrooms
• Vision correction: regular eye checks, updated prescriptions
• Medication review: sedatives, blood pressure medications, and polypharmacy increase fall risk
• Footwear: well-fitting, non-slip shoes

Lifestyle

• Stop smoking — associated with improved bone density over time
• Limit alcohol to ≤2 standard drinks per day
• Maintain healthy body weight — both underweight and obesity-related falls increase fracture risk

What Clinicians May Discuss

This is an overview of clinical approaches — not a recommendation to start or change any treatment. All decisions require individual clinical assessment.

Screening Recommendations

• USPSTF recommends DXA screening for all women aged 65+ and younger postmenopausal women with risk factors.
• Men: screening recommendations vary. Consider DXA for men aged 70+ or younger men with risk factors (corticosteroid use, low body weight, prior fracture).
• FRAX® tool: a WHO-developed calculator that estimates 10-year fracture probability using clinical risk factors, with or without DXA results.

Pharmacological Treatment

Clinicians may discuss medications for people with osteoporosis or high fracture risk. Common classes include:

• Bisphosphonates — the most commonly prescribed first-line treatment. Reduce bone resorption and fracture risk.
• Denosumab — a monoclonal antibody that inhibits bone resorption. It is given by clinician-supervised injection on a medical schedule.
• Selective oestrogen receptor modulators (SERMs) — e.g. raloxifene. Reduce vertebral fracture risk in postmenopausal women.
• Anabolic agents — e.g. teriparatide, romosozumab. Stimulate bone formation. Reserved for severe osteoporosis or treatment failure.
• Hormone replacement therapy (HRT) — protects bone during use but decisions involve weighing benefits against other risks. Discuss with a clinician.

Treatment decisions depend on fracture risk level, age, other medical conditions, and patient preferences. This article does not recommend any specific medication or dose.

Monitoring

• Repeat DXA typically every 2–5 years during treatment to assess response
• Bone turnover markers (blood/urine tests) may be used to monitor treatment adherence and response
• Treatment duration and "drug holidays" are individualised decisions made with a clinician

When To Seek Urgent Help

Routine evaluation (GP appointment):

• You are over 50 and have not had a bone density assessment despite risk factors
• You have lost height (>3 cm) or developed a stooped posture
• You have had a fracture from a minor fall or minimal trauma
• You are starting or have been on corticosteroids for more than 3 months
• You have a family history of osteoporosis or hip fracture

Urgent evaluation (same-day or emergency):

• Sudden severe back pain — especially mid-back or lower back after bending, lifting, or a minor fall. May indicate a vertebral compression fracture.
• Hip pain after a fall — inability to bear weight or shortened/rotated leg after falling. Possible hip fracture requiring emergency assessment.
• Any fracture from minimal trauma — a fall from standing height or less that results in a fracture warrants urgent medical review and subsequent bone health assessment.
• Sudden loss of height or new kyphosis — may indicate one or more vertebral fractures.

A fragility fracture is a medical event that requires both acute treatment and long-term bone health review. Do not dismiss fractures from minor falls as "just a fall" — they may indicate underlying osteoporosis.

Questions To Ask Your Doctor

• Should I have a bone density (DXA) scan given my age and risk factors?
• What does my T-score mean, and what is my estimated fracture risk?
• Are there reversible causes of bone loss I should be tested for (vitamin D, thyroid, coeliac)?
• What lifestyle changes would make the most difference for my bone health?
• Do I need medication for osteoporosis, and what are the benefits and risks?
• How long should I take osteoporosis medication, and when should we reassess?
• I've had a fracture from a minor fall — should my bone health be investigated?
• What can I do to reduce my risk of falling?
• My parent had a hip fracture — what does this mean for my own risk?

Sources

• WHO. Assessment of fracture risk and its application to screening for postmenopausal osteoporosis. WHO Technical Report Series 843. 1994.
• NIH/NIAMS. Osteoporosis Overview. niams.nih.gov (2023)
• International Osteoporosis Foundation (IOF). Epidemiology, burden, and treatment of osteoporosis. osteoporosis.foundation
• Bone Health & Osteoporosis Foundation (NOF). Clinician's Guide to Prevention and Treatment of Osteoporosis. 2022.
• USPSTF. Screening for Osteoporosis to Prevent Fractures. JAMA. 2018;319(24):2521–2531.
• NICE. Osteoporosis: assessing the risk of fragility fracture (CG146). nice.org.uk
• Kanis JA, et al. FRAX and the assessment of fracture probability in men and women from the UK. Osteoporos Int. 2008.
• Compston J, et al. UK clinical guideline for the prevention and treatment of osteoporosis. Arch Osteoporos. 2017.
• Camacho PM, et al. AACE/ACE Clinical Practice Guidelines for Diagnosis and Treatment of Postmenopausal Osteoporosis. Endocr Pract. 2020.
• Singapore MOH. Clinical Practice Guidelines: Osteoporosis. moh.gov.sg