Osteoporosis
Osteoporosis is defined by a T-score of -2.5 or lower, a fragility fracture regardless of bone density, or osteopenia with elevated FRAX-calculated fracture risk, per the Endocrine Society Clinical Practice Guideline (2019).
Symptoms
Often silent until a fracture occurs -- a vertebral compression fracture can cause height loss or back pain without an obvious injury; a hip or wrist fracture from a fall that wouldn't normally break a bone is often the first sign.
Causes and risk
Age, menopause (estrogen loss accelerates bone loss), low body weight, family history, smoking, and long-term steroid use are the main risk factors.
How it is evaluated
DEXA screening for women 65 and older (or younger with risk factors), per 2025 USPSTF guidance, combined with FRAX fracture-risk calculation.
Treatment
Bisphosphonates are first-line antiresorptive therapy for most patients; denosumab is an alternative. For very-high-risk patients, anabolic agents (teriparatide, abaloparatide, romosozumab) are used first and must be followed by an antiresorptive to maintain the gained bone density. Denosumab discontinuation requires careful transition planning to avoid rebound bone loss.
When to seek care
A fracture from a fall that wouldn't normally cause one, or sudden severe back pain (possible vertebral compression fracture), needs prompt evaluation.