What is osteoporosis?

What is osteoporosis disease, and how is it diagnosed?

Osteoporosis disease means bone mineral density has fallen low enough that bone is weaker and more likely to fracture. It tends to stay silent along the way, which is why a scan tells you more than waiting for signs.

A DEXA scan (often written DXA in US reports) of the hip and spine is the standard way to measure bone density. The result comes back as a T-score, often alongside a FRAX estimate of your 10-year fracture risk. The USPSTF suggests a scan from 65, or earlier after menopause for women with risk factors: early menopause, low body weight, steroid use, a family history of hip fracture or smoking. In the UK, a GP assesses your risk first and may then refer you for the scan.

What does the evidence say about bone loss and protecting bone?

The evidence shows a simple pattern across a woman's life: bone is built early, holds fairly steady through the reproductive years, is lost fastest around the final period, and responds to loading, nutrients and, for some women, medication. Around 90% of adult bone mass is in place by age 18, according to the National Osteoporosis Foundation's position statement on peak bone mass, so the bone built in girlhood is the reserve drawn on after menopause.

The Study of Women's Health Across the Nation (SWAN) found that bone loss clusters in a window of roughly three years, from about one year before the final period to two years after, with an average of 7.38% of bone density lost at the lumbar spine across it. That makes the lead-up to menopause a useful time to look at bone health. Options usually discussed are hormone therapy (HRT in the UK), heavy and impact loading, calcium and vitamin D; whether hormone therapy fits is a decision for you and your own provider.

Loading exercise is the part many women can begin for themselves. Impact and heavy resistance work load the hip and spine, which is why weight bearing exercises for osteoporosis get so much attention. In the LIFTMOR trial, supervised heavy lifting improved bone density even in women who already had low bone mass.

Osteoporosis medication has the clearest fracture data. In the review behind the 2025 USPSTF recommendation, bisphosphonates cut spine fractures by about half, or about 18 fewer per 1,000 treated, while the hip benefit was less certain. The review found the harms small in women, with no significant rise in serious adverse events with bisphosphonates or denosumab, and osteonecrosis of the jaw was rare. In the UK, NHS guidance on osteoporosis treatments names bisphosphonates and anabolic agents among the classes used.

How much calcium, vitamin D and exercise do bones need?

For calcium, a sensible daily target is 1,200 mg in the US from age 51 (700 mg in the UK, or 1,000 mg if bones are thinning). Many women weigh food sources against a calcium supplement to cover any gap, a choice worth talking through with a primary care provider (a GP in the UK).

Vitamin D sits alongside calcium in bone guidance, and your provider can advise on a dose that suits your own level.

For exercise, a good place to start is two strength sessions a week, learning the lifts with good technique and adding load gradually. The LIFTMOR trial dose, one lift of about 5 sets of 5 at roughly 85% of your maximum, done fed rather than fasted, is where that progression leads over time, with supervision.

The Royal Osteoporosis Society's 2019 Strong, Steady and Straight consensus supports exercising with osteoporosis. Many women find it helps to keep the spine neutral when lifting and leave out repeated or loaded forward bending such as sit-ups and toe touches. A physical therapist (physiotherapist in the UK) can tailor a plan.

What did the studies show, and what did they leave open?

LIFTMOR tested one supervised program, so it supports supervision and gradual progression for women with low bone mass. It does not show that every lifting protocol suits every woman.

SWAN observed women over time and did not assign treatments, so it describes when bone is lost as estrogen falls, not which approach prevents the loss for a given woman.

The USPSTF review measured treatments by fractures prevented, so it speaks to lowering fracture risk rather than to curing osteoporosis. It noted that atypical femur fractures appeared only in observational studies, which may be confounded, and that FRAX has no fixed cutoff, so a result works best as the start of a conversation.

The CDC prevalence figures come from its 2017 to 2018 national survey, reported in 2021: 19.6% of women aged 50 and over had osteoporosis, up from 14.0% in 2007 to 2008, against 4.4% of men (about 1 in 23). The Bone Health and Osteoporosis Foundation's estimate that one in two women aged 50 and over will break a bone due to osteoporosis is a different kind of number: a projection across the rest of life, not a count of who has the condition today.

Next steps

A good place to start is wherever you are now. If you are in your 40s or approaching menopause, it's worth asking a primary care provider or GP whether a scan makes sense now or later. If you'd like to add heavy lifting, a few supervised sessions can help you build up gradually and with confidence. And after a break from a minor fall, or if you notice you are getting shorter, many women find it helps to ask for a bone health assessment at that point. Bone health is not one size fits all, so take what fits your body, your history and your preferences.