Bone Density Test (DEXA): Normal Range & T-score Explained

Quick answer

A bone density test (DEXA) is a quick, safe low-dose X-ray that measures bone density at the lumbar spine and hip. The key result is the T-score: −1 or higher is normal, between −1 and −2.5 is low bone mass (osteopenia), and −2.5 or lower is osteoporosis. It is recommended for women from 65 and men from 70, and earlier with risk factors or after a fracture from a minor fall.

✅ Last medically reviewed by Prof. Dr. Ibrahim Shaarawi, Professor of Orthopaedic Surgery, on 5 October 2026

About your surgeon: Prof. Dr. Ibrahim Shaarawi

Professor of Orthopaedic Surgery, Faculty of Medicine, Ain Shams University.
Visiting Professor of Orthopaedic Surgery, Ohio, USA.
Certificate in complex fractures and trauma, University of Maryland, USA.
He treats fragility fractures in older adults: he has performed 1,400 bipolar hip hemiarthroplasties (used mainly for femoral neck fractures), 650 total hip replacements and 250 dual-mobility hips, plus 55 reverse shoulder replacements.
Rated 4.9 and 5.0 on Google by about 300 patients.

He sees patients at his clinics in Nasr City, Mohandeseen and New Cairo (5th Settlement).

Many patients bring a DEXA report full of numbers they do not understand, and some worry needlessly about a negative value. This article explains how to read the result and what comes next, as part of our guide to osteoporosis.

What is a DEXA scan?

Dual-energy X-ray absorptiometry (DXA or DEXA) uses a very low dose of X-rays. You lie on the table for 10–20 minutes with no pain or injections while the scanner measures the mineral content of bone, usually at the lumbar spine and hip (total hip and femoral neck), sometimes the forearm. The radiation dose is lower than a standard chest X-ray.

Patient having a DEXA bone density scan — A DEXA bone density scan is quick and painless

How to read your result: the T-score

The T-score compares your bone density with that of a healthy young adult of the same sex, expressed in standard deviations. It is used for women after menopause and men over 50, under the WHO classification:

T-score	Interpretation	What it means for you
−1 or higher	Normal	Keep up diet, exercise and vitamin D
Between −1 and −2.5	Low bone mass (osteopenia)	Assess risk factors; may need treatment if fracture risk is high
−2.5 or lower	Osteoporosis	Usually needs medication
−2.5 or lower with a fragility fracture	Severe (established) osteoporosis	Prompt treatment, possibly a bone-building drug

Table 1: T-score interpretation under the WHO definition.

Example: a T-score of −1.8 means low bone mass, not osteoporosis; −2.7 means osteoporosis. The lowest value among spine and hip sites determines the diagnosis.

DEXA report of the lumbar spine with T-scores in the osteoporosis range — A lumbar spine DEXA report: green is normal, yellow is osteopenia and red is osteoporosis — Image: Jmarchn / Wikimedia Commons, CC BY-SA 3.0

Video: preventing fractures after 50

Prof. Dr. Ibrahim Shaarawi gives advice on preventing fractures after age 50 (in Arabic).

What is a Z-score?

The Z-score compares your bone density with people of your own age and sex. It is used for premenopausal women, men under 50 and children. A Z-score of −2 or lower is “below the expected range for age” and calls for a search for secondary causes such as osteomalacia, endocrine disorders, malabsorption or medicines.

Who needs a bone density test?

Women aged 65 or older and men aged 70 or older.
Postmenopausal women and men aged 50–69 with risk factors: low weight, smoking, a parent with a hip fracture, early menopause.
Anyone with a fracture after a minor fall after age 50 (wrist, spine, hip, shoulder).
Oral steroid use for 3 months or more.
Conditions such as rheumatoid arthritis, hyperparathyroidism, malabsorption, and after bariatric surgery.
Before and during treatment with bone-weakening drugs such as some breast and prostate cancer therapies.
Monitoring osteoporosis treatment.

For women specifically, see osteoporosis symptoms in women.

How to prepare

Stop calcium tablets 24 hours before the scan.
Tell the staff about any contrast, barium or nuclear medicine test in the previous two weeks.
Tell the doctor if you might be pregnant.
Wear comfortable clothes without metal.
Have follow-up scans on the same machine and at the same centre when possible.

Limitations: when the result can mislead

Spinal arthritis and bone spurs in older people can falsely raise spine readings, so we rely more on the hip.
Old vertebral fractures or metal implants in the measured area.
Osteomalacia gives low density that mimics osteoporosis, so we check vitamin D and alkaline phosphatase before starting osteoporosis drugs.
Density alone does not capture all fracture risk; we combine it with age, previous fractures and risk factors in the FRAX calculator.

Key numbers to know

In the FREEDOM trial, Prolia cut new vertebral fractures by 68% (2.3% vs 7.2%) and hip fractures by 40% (Cummings et al., NEJM 2009).
In the HORIZON trial, yearly zoledronic acid cut vertebral fractures by 70% and hip fractures by 41% over 3 years (Black et al., NEJM 2007).
Calcium supplements lowered overall fracture risk by about 11% in randomised trials but did not reduce hip fractures (Bolland et al., BMJ 2015).

Treatment	When we use it	Notes
Calcium, vitamin D, exercise and fall prevention	Everyone with or at risk of osteoporosis	The foundation, but not enough alone in established osteoporosis
Bisphosphonate tablets	Osteoporosis without multiple fractures	Taken correctly on an empty stomach
Zoledronic acid (yearly infusion)	People preferring a yearly dose with good kidney function	Cut vertebral fractures by 70% in HORIZON
Prolia injection every 6 months	High fracture risk or moderate kidney disease	Must not be stopped abruptly without a follow-on drug
Bone-building drugs (teriparatide or romosozumab)	Severe osteoporosis and multiple fractures	Followed by a maintenance drug after the course
Fracture surgery (fixation or replacement)	When a hip or other fracture occurs	Together with starting osteoporosis treatment to prevent the next fracture

Table: treatment options for osteoporosis

At Prof. Dr. Ibrahim Shaarawi’s clinics in Nasr City, Mohandeseen and New Cairo (5th Settlement) we review your vitamin D, calcium and bone density results and examine the cause of pain or fracture before deciding on the right dose or osteoporosis treatment.

What happens after the result?

Result	Usual next step
Normal	Adequate vitamin D, dietary calcium, exercise, repeat scan depending on risk
Osteopenia	FRAX risk calculation, treat causes, medication if risk is high
Osteoporosis	Baseline tests, then treatment such as bisphosphonates, the 6-monthly Prolia injection or zoledronic acid
Osteoporosis with fractures	Potent, possibly bone-building treatment and fall prevention

Table 2: Next steps after a bone density result.

During treatment we usually repeat the scan every one to two years on the same machine. Treatment options are in osteoporosis and the role of vitamin D in vitamin D and fractures in older adults.

Frequently asked questions about the bone density test

What is a normal bone density result?

A T-score of −1 or higher is normal. Between −1 and −2.5 means low bone mass (osteopenia), and −2.5 or lower means osteoporosis.

What is the difference between a T-score and a Z-score?

The T-score compares you with a healthy young adult and is used after menopause and in men over 50; the Z-score compares you with people your age and is used in younger adults and children.

Does a DEXA scan involve harmful radiation?

The dose is very low — less than a standard chest X-ray — and the test is safe, painless and takes 10–20 minutes.

How often should a bone density test be repeated?

Usually every one to two years during osteoporosis treatment; if normal, the interval depends on your risk factors. Use the same machine when possible.

Does osteopenia need treatment?

Not always. It depends on fracture risk calculated from age, previous fractures and risk factors; many people need only vitamin D, calcium and exercise, and some need medication.

To have your bones assessed and your tests reviewed, book a consultation, call +20 155 240 4488 or message us on WhatsApp at +20 155 554 7181.

Medically reviewed by Prof. Dr. Ibrahim Shaarawi, Professor of Orthopaedic Surgery. This article is general medical education and does not replace an examination or the treatment plan your doctor sets for you. See our medical disclaimer.

Related vitamin D and bone health guides

Related guides on bone density and osteoporosis:

Bone Density Test (DEXA Scan): Normal Range, T-score, Z-score and When to Have One