Severe osteoporosis is characterized by a T-score of -2.5 or lower with:

• A. No fractures.
• B. One or more fractures.
• C. Normal BMD.
• D. Only vertebral fractures.

Answer: (B)

Severe osteoporosis is defined as osteoporosis with a fragility fracture. A T-score of -2.5 or lower shows osteoporosis by bone density criteria, but the addition of a fracture demonstrates that the bone weakness has led to a clinical fracture, which marks the disease as severe. Fractures can occur at any typical fragility sites, not just one location, so describing it as having one or more fractures captures the necessary clinical consequence of the low bone density. The other options miss this key piece (the fracture) or contradict osteoporosis entirely (normal BMD). Vertebral fractures are common in osteoporosis, but the important point is the presence of a fragility fracture, not the limitation to a specific site.