What are the diagnostic criteria for osteoporosis?

From the Guidelines

Osteoporosis is diagnosed primarily using bone mineral density (BMD) measurements obtained through dual-energy X-ray absorptiometry (DXA) scans, with a T-score of -2.5 or lower at the lumbar spine, femoral neck, or total hip indicating osteoporosis, as defined by the World Health Organization criteria 1. The diagnostic criteria for osteoporosis are based on BMD measurements, which can be obtained through DXA scans.

• The World Health Organization criteria define osteoporosis as a BMD T-score of -2.5 or lower at the lumbar spine, femoral neck, or total hip.
• T-scores compare an individual's bone density to that of a healthy young adult of the same sex, with each standard deviation below normal represented as a negative value.
• A T-score between -1.0 and -2.5 indicates osteopenia (low bone mass), while a score above -1.0 is considered normal.
• Clinical diagnosis may also be made in patients with a fragility fracture (a fracture occurring from minimal trauma, such as a fall from standing height) regardless of BMD values.
• Risk assessment tools like FRAX can supplement DXA results by calculating a 10-year probability of fracture based on clinical risk factors including age, sex, BMI, previous fractures, parental hip fracture history, smoking, alcohol use, and certain medical conditions 1. The most recent and highest quality study, published in 2025, supports the use of DXA scans and the World Health Organization criteria for diagnosing osteoporosis 1.
• The study recommends that DXA BMD measurement should be performed at the lumbar spine, total hip, femoral neck, and, if indicated, one-third radius.
• The study also suggests that each DXA facility should determine its precision error and calculate the least significant change (LSC), to be repeated when a new DXA system is installed 1. Overall, the diagnostic criteria for osteoporosis are well-established and based on BMD measurements obtained through DXA scans, with a T-score of -2.5 or lower indicating osteoporosis.

From the FDA Drug Label

Osteoporosis is characterized by low bone mass that leads to an increased risk of fracture. The diagnosis can be confirmed by the finding of low bone mass, evidence of fracture on x-ray, a history of osteoporotic fracture, or height loss or kyphosis, indicative of vertebral (spinal) fracture

The diagnostic criteria for osteoporosis include:

• Low bone mass
• Evidence of fracture on x-ray
• History of osteoporotic fracture
• Height loss or kyphosis, indicative of vertebral (spinal) fracture 2

From the Research

Diagnostic Criteria for Osteoporosis

The diagnostic criteria for osteoporosis are based on the T-score calculated from bone mineral density (BMD) measurements 3, 4, 5, 6.

• A T-score of -2.5 or lower is indicative of osteoporosis 4, 5.
• The T-score is calculated by comparing an individual's BMD to the mean value of a young healthy reference population, with the difference expressed as a standard deviation (SD) 4.
• The World Health Organization (WHO) has established diagnostic categories based on T-scores, including normal, osteopenia, and osteoporosis 4, 5.
• In addition to T-scores, Z-scores can also be used to describe the number of SDs by which the BMD in an individual differs from the mean value expected for age and sex 4, 5.
• Z-scores can provide information about an individual's fracture risk compared to peers, but are not intended for diagnosis of osteoporosis in adults 4.

Measurement of Bone Mineral Density (BMD)

BMD can be measured at various skeletal sites using several different methods, including dual-energy X-ray absorptiometry (DXA) 4, 6.

• DXA is considered the gold standard for noninvasive diagnosis of osteoporosis 4, 6.
• The indications for BMD testing, clinical utility of BMD, and frequency of follow-up testing are important considerations in the diagnosis and management of osteoporosis 6.

Assessment of Fracture Risk

Assessment of fracture risk should take into account specific risk factors that contribute to fracture risk, as well as BMD 7.

• The presence of several risk factors can be associated with a fracture risk greater than can be accounted for by BMD alone 7.
• Tools such as FRAX and QFracture can be used to estimate 10-year predicted absolute fracture risk 7.
• BMD should not be routinely measured to assess fracture risk without prior assessment using FRAX or QFracture 7.