Causes & risk factors
Bone loss has predictable drivers — the loss of estrogen at menopause above all, plus aging, the biology of bone loss in men, and a long list of medications and conditions that quietly weaken the skeleton. Knowing which apply to you is the first step in judging your risk.
Key takeaways
- Estrogen loss at menopause is the single biggest driver of bone loss in women — loss can run ~6× faster in the menopausal transition.
- Fracture risk roughly doubles every 7–8 years after age 50.
- Men get osteoporosis too — about a decade later — and are diagnosed and treated far less often than women.
- Many cases are secondary to medications (especially glucocorticoids) or other conditions, which changes the workup.
Menopause & estrogen loss
Estrogen restrains the bone-resorbing osteoclast. As long as estrogen is present, it holds resorption in check and keeps remodeling balanced. When estrogen falls at menopause, that brake comes off: resorption accelerates, formation can't keep pace, and bone is lost rapidly — a study estimated women lose bone about 6× faster during the menopausal transition than in the 25 years before it. This is why postmenopausal osteoporosis is the most common form of the disease and why women reach a lower peak bone mass and carry a higher lifetime fracture risk than men.
The loss is fastest in the first several years around the final period, then continues more slowly. This early, rapid phase is part of why bone health deserves attention at menopause, not decades later after a fracture. (For hormone therapy's role, see Treatment; for the wider hormonal picture, our sister site MenoExperts covers menopause in depth.)
Aging & bone loss
Independent of menopause, bone is lost with age in both sexes. Remodeling becomes less efficient, osteoblast function declines, calcium absorption falls, vitamin D status often drops, and falls become more likely. The result is a steady rise in fracture risk: after age 50, the risk of an osteoporotic fracture roughly doubles every 7 to 8 years. Low body weight (a low BMI) is one of the most consistent predictors of fracture across all ages.
What this means for you
Risk factors add up. Being postmenopausal, older, thin, and having a parent who broke a hip aren't separate boxes — together they build a picture of your absolute fracture risk, which is exactly what a tool like FRAX is designed to estimate (see Diagnosis).
Osteoporosis in men
Osteoporosis is not only a women's disease. Up to 1 in 4 men over 50 will break a bone because of it. In men, sex-hormone decline is more gradual — and, notably, falling estradiol (produced in men from testosterone) correlates with bone loss even more strongly than falling testosterone itself. Fragility fractures climb in men about a decade later than in women, but their consequences are at least as serious.
The bigger problem is neglect. Men are screened for osteoporosis far less often, are less likely to be tested even after a hip fracture, and are less likely to be treated afterward. In one comparison, osteoporosis screening after hip fracture occurred in about 12% of women but only 5% of men. A fragility fracture in a man deserves the same urgent evaluation it would prompt in a woman. (For low testosterone specifically, see our sister site TestoExperts.)
Secondary causes & medications
A substantial share of osteoporosis is secondary — caused or worsened by another condition or a medication rather than by menopause and aging alone. Identifying these matters, because treating the underlying cause is part of the fix, and because unexplained or unusually severe bone loss should trigger a workup.
| Category | Examples |
|---|---|
| Medications | Glucocorticoids (the most common cause of drug-induced osteoporosis), aromatase inhibitors, androgen-deprivation therapy, some anti-seizure drugs, long-term proton-pump inhibitors, excess thyroid hormone. |
| Endocrine | Hypogonadism, hyperparathyroidism, hyperthyroidism, Cushing's syndrome, type 1 and type 2 diabetes. |
| GI & nutrition | Celiac disease, inflammatory bowel disease, bariatric surgery, malabsorption, low body weight, eating disorders. |
| Lifestyle | Excess alcohol, tobacco use, physical inactivity, low calcium and vitamin D intake. |
| Other | Rheumatoid arthritis and other inflammatory disease, chronic kidney disease, some cancers, immobilization. |
For cliniciansSecondary-cause workup we consider before or alongside therapy
For newly diagnosed osteoporosis — and especially for premenopausal women, younger men, Z-scores well below expected, or disproportionate severity — we consider CBC, comprehensive metabolic panel (calcium, renal, hepatic), 25-OH vitamin D, PTH, TSH, 24-hour urinary calcium, and testosterone in men, with celiac serologies, SPEP/serum free light chains, and cortisol testing added where the picture warrants. Correcting a secondary driver (e.g., vitamin D repletion, hyperthyroidism, hyperparathyroidism) is part of treatment, not a substitute for it in the high-risk patient.
Not sure which risk factors apply to you?
A proper fracture-risk assessment turns a list of worries into a clear plan. Board-certified endocrinologists, straight answers.