Interpret your DEXA scan T-score result using WHO classification criteria for osteoporosis screening
This calculator is for informational purposes only and does not constitute medical advice. T-score interpretation should be performed by a qualified healthcare professional. Always consult your GP or specialist.
Bone density is a measure of the mineral content in your bones, and it is one of the most important indicators of bone health and fracture risk. A DEXA scan (dual-energy X-ray absorptiometry) is the gold-standard test for measuring bone density, and the result is expressed as a T-score. The World Health Organisation (WHO) uses the T-score to classify bone density into three categories: normal (T-score of -1.0 or above), osteopenia (T-score between -1.0 and -2.5), and osteoporosis (T-score of -2.5 or below). Osteoporosis affects approximately 3 million people in the UK, according to the Royal Osteoporosis Society. It is sometimes called a "silent disease" because bone loss occurs without symptoms until a fracture happens. Postmenopausal women are at the highest risk due to the decline in oestrogen, but men and younger individuals can also be affected. The NHS recommends bone density testing for individuals with risk factors such as a previous fragility fracture, long-term corticosteroid use, early menopause (before age 45), a family history of hip fracture, or conditions that affect nutrient absorption. This calculator helps you interpret your DEXA scan T-score using the WHO classification system and provides guidance based on NICE (National Institute for Health and Care Excellence) osteoporosis guidelines. It also estimates your fracture risk level and indicates when NHS treatment may be recommended. Please note that this tool is for informational purposes only -- your healthcare provider should interpret your results in the context of your full medical history.
To interpret your bone density T-score: 1. Enter your T-score from your DEXA scan result. This is the number provided by your radiologist or GP, typically ranging from +2 to -4. If you are unsure of your T-score, check your scan report or ask your healthcare provider. 2. Enter your age in years. Age is an important factor in fracture risk assessment, and the calculator will note if the Z-score may be more appropriate for your age group (under 50). 3. Select your sex. Osteoporosis risk factors and treatment thresholds can differ between men and women. 4. Indicate whether you have a history of fragility fractures. A fragility fracture is one that occurs from a fall from standing height or less. Previous fractures significantly increase the risk of future fractures and may change the classification from osteoporosis to severe osteoporosis. 5. View your results. The calculator displays your WHO classification, estimated fracture risk level, treatment recommendations based on NICE guidelines, and a visual chart showing where your T-score falls on the diagnostic scale.
The T-score compares your bone mineral density (BMD) to that of a healthy young adult (typically a 30-year-old of the same sex). It is calculated as the number of standard deviations your BMD is above or below this reference value. The WHO classification system defines three diagnostic categories: - Normal: T-score of -1.0 or above (your bone density is within 1 standard deviation of the young adult mean) - Osteopenia: T-score between -1.0 and -2.5 (mild to moderate bone thinning, between 1 and 2.5 standard deviations below the mean) - Osteoporosis: T-score of -2.5 or below (significant bone loss, more than 2.5 standard deviations below the mean) - Severe osteoporosis: T-score of -2.5 or below with one or more fragility fractures Fracture risk assessment combines the T-score with clinical risk factors. The FRAX tool (Fracture Risk Assessment Tool) is commonly used by clinicians to estimate 10-year fracture probability, incorporating factors such as age, sex, BMI, previous fractures, parental hip fracture history, smoking, alcohol intake, glucocorticoid use, and secondary causes of osteoporosis. For individuals under 50, the Z-score is generally preferred over the T-score. The Z-score compares your BMD to others of the same age and sex, which is more clinically meaningful when the expected bone density is still high.
The Royal Osteoporosis Society and NICE recommend that all adults maintain bone health through adequate calcium intake (at least 700mg per day from diet, or supplements if needed), vitamin D supplementation (10mcg per day, as recommended by the NHS), and regular weight-bearing and resistance exercise. Smoking cessation and limiting alcohol intake also help protect bone density. If you have been diagnosed with osteopenia or osteoporosis, your GP or specialist will discuss treatment options and monitoring schedules with you. NICE recommends reassessment of fracture risk if there is a change in clinical circumstances, such as a new fracture, a new medical condition, or a change in medication.