A person with bone density 2.5 standard deviations below the young adult mean is diagnosed with which condition?

The correct condition for an individual with bone density that is 2.5 standard deviations below the young adult mean is osteoporosis. This diagnosis is based on the World Health Organization (WHO) criteria for osteoporosis, which specifically states that osteoporosis is defined as a bone mineral density (BMD) that falls 2.5 standard deviations or more below the mean peak bone mass of healthy young adults, typically measured by dual-energy X-ray absorptiometry (DEXA) scans.

Osteoporosis is characterized by an increased risk of fractures due to decreased bone strength, making awareness and diagnosis important for prevention and management. Individuals diagnosed with osteoporosis may not have any symptoms until a fracture occurs, highlighting the significance of regular screening in populations at risk.

In contrast, osteopenia refers to a condition where bone density is lower than normal but not to the extent classified as osteoporosis, typically falling between 1.0 and 2.5 standard deviations below the mean. Conditions such as arthritis and Paget's disease have different underlying causes and characteristics unrelated to the specific threshold of bone density measured in this context. Therefore, recognizing the distinction between these conditions is crucial in making an accurate diagnosis and determining the appropriate management strategies for bone health.