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Your skeleton is not static. It is constantly being broken down and rebuilt, and the balance between those two processes shifts with age, hormones, medications, and disease. The femoral neck T-score is a single number that captures how much bone density you have lost at the most fracture-prone section of your hip, and it is one of the most powerful predictors of whether you will break a bone in the next ten years. You can order this test, interpret the result, and use it to make decisions about your bone health right now.
The femoral neck is the narrow angled segment of bone that connects the ball of your hip to the main shaft of your thigh bone. It is the site most likely to break in a fall, and it loses density faster than almost any other skeletal region as you age. The test used to measure it is called dual-energy X-ray absorptiometry, or bone density scanning (DEXA). It measures how much mineral is packed into a square centimeter of bone at that site.
The result is expressed as a T-score. A T-score is the number of standard deviations your bone density falls above or below the average peak bone density of a healthy young adult between ages 20 and 29. A score of 0 means your density matches that young adult average exactly. A score of negative 1.0 means you are one standard deviation below that average, and so on. The further below zero your score falls, the more bone you have lost relative to your peak.
The World Health Organization classification applies to postmenopausal women and men aged 50 and older. If your T-score is at or above negative 1.0, your bone density is considered normal. If it falls between negative 1.0 and negative 2.5, you have low bone mass, sometimes called osteopenia, meaning your bones are below average but not yet in the range that defines osteoporosis. If your T-score is at or below negative 2.5, you meet the definition of osteoporosis.
| T-Score Range | Classification | What It Means for You |
|---|---|---|
| At or above negative 1.0 | Normal | Your bone density is in the healthy range for a young adult reference population |
| Between negative 1.0 and negative 2.5 | Low bone mass (osteopenia) | You have lost measurable bone; your fracture risk is intermediate and warrants a full risk assessment using the FRAX tool |
| At or below negative 2.5 | Osteoporosis | You have significant bone loss; treatment is typically indicated regardless of other risk factors |
| Approximately negative 3.0 or lower | Severe osteoporosis | Very high fracture risk; bone-building therapy rather than bone-preserving therapy may be preferred |
What this means for you: a T-score of negative 2.5 or lower is not just a label. It is the threshold at which US guidelines recommend starting medication to reduce your fracture risk, so knowing your exact number determines whether you are in a watchful monitoring category or an active treatment category.
Bone is a living structure made partly of a protein scaffold and partly of mineral crystals. As mineral density falls, the structure becomes more porous and less able to absorb impact without cracking. The femoral neck is especially vulnerable because it bears the full force of a sideways fall and has relatively little soft tissue around it to absorb shock.
Each one standard deviation decrease in femoral neck bone density is associated with a 1.8-fold higher hip fracture risk in fully adjusted analyses. That relationship compounds: losing two standard deviations of density does not just double your risk, it multiplies it. Women over age 85 have a ten-fold higher hip fracture risk compared to women in their 60s, and the femoral neck T-score is a core part of why that gap exists.
After a hip fracture, the consequences are severe. Approximately 20% of people are institutionalized afterward, and mortality risk doubles within one year. This is why identifying bone loss before a fracture occurs matters so much.
Some groups carry elevated fracture risk beyond what a T-score alone would suggest, and knowing your group matters for interpreting your result accurately.
If you have type 2 diabetes, your fracture risk at any given T-score is higher than it would be for someone without diabetes, particularly if you use insulin. Standard T-score thresholds may underestimate your true risk. A Schwartz et al. study of older adults with type 2 diabetes demonstrated this gap directly, with insulin users showing substantially higher fracture rates than non-diabetic adults with equivalent bone density scores.
If you take corticosteroids such as prednisone, bone loss can begin within three to six months of starting the medication, before your T-score has declined significantly. People receiving 7.5 mg or more of prednisone daily face a five-fold higher vertebral fracture risk and a 2.2-fold higher hip fracture risk. At very high doses of 30 mg per day or with cumulative doses above 5 grams, vertebral fracture risk rises fourteen-fold. If your dose exceeds 7.5 mg per day, standard FRAX calculations underestimate your risk; guideline adjustments of plus 15% for major fractures and plus 20% for hip fractures are recommended.
If you have chronic kidney disease, lower kidney filtration rates independently increase fracture risk. In the CRIC study of people with chronic kidney disease, kidney failure requiring dialysis was associated with a 4.5-fold higher fracture risk compared to those with normal kidney function. Each 10-unit decline in kidney filtration rate corresponded to a 20% increase in fracture risk.
If you are an older man, hip fractures tend to occur at T-scores roughly 0.5 to 0.6 units higher than in women. The mean hip fracture T-score in men is approximately negative 2.33, compared to negative 2.9 in women. Some researchers have proposed that a threshold of negative 2.0 better identifies at-risk older men, though this has not yet been adopted into standard guidelines.
Other populations with meaningfully elevated risk include people with a body weight under 58 kg or a body mass index below 18.5, who have approximately a three-fold higher hip fracture risk. People with rheumatoid arthritis, a history of premature menopause before age 40, current smoking, or heavy alcohol use also carry substantially elevated risk. Smokers and heavy drinkers face approximately 1.5 to 2 times higher fracture odds.
One critical point: approximately 70% of osteoporotic fractures occur in people whose T-score does not technically meet the osteoporosis threshold. This means the T-score is necessary but not sufficient. It must be combined with clinical risk factors using the FRAX tool to calculate your 10-year fracture probability accurately.
Pharmacological therapy is the most potent way to improve a low T-score. US guidelines recommend starting medication if your T-score is at or below negative 2.5 at the femoral neck, total hip, or lumbar spine; if you have had a hip or vertebral fracture regardless of T-score; or if your T-score is between negative 1.0 and negative 2.5 and your FRAX 10-year probability is at or above 20% for major osteoporotic fracture or at or above 3% for hip fracture. The goal set by the 2024 ASBMR/BHOF task force is to bring the T-score above negative 2.5 as a minimum treatment target.
For people on long-term glucocorticoids, the evidence supports prophylactic bone-protective therapy early, before significant T-score decline, because fracture risk rises within the first three to six months of therapy. Waiting for the T-score to cross the negative 2.5 threshold may mean waiting too long in this group.
Several medications prescribed for other conditions accelerate bone loss and lower the T-score over time. These include anticonvulsants, aromatase inhibitors used in breast cancer treatment, gonadotropin-releasing hormone agonists, proton pump inhibitors, and loop diuretics. Reviewing your medication list with a clinician is a meaningful step if any of these apply to you.
Modifiable lifestyle factors such as smoking cessation and reducing heavy alcohol use are supported by fracture outcome data, though direct T-score effect sizes from randomized trials are not available in the research provided. Falls are the proximate cause of approximately 90% of hip fractures, meaning fall prevention through strength training, balance work, and home safety measures reduces fracture risk through a pathway the T-score does not directly capture.
Monitoring frequency after starting treatment is typically every one to three years by DEXA. A clinically meaningful change at the femoral neck generally requires a shift of more than 3 to 5%, depending on the specific DXA machine's measurement precision.