Bone Health in Your 40s: What Changes, and What the UK Guidelines Say

What actually changes about your bones in your 40s?

Very little that you can feel — which is exactly the problem. By your 40s the building phase is over and the maintenance phase has begun. The Royal Osteoporosis Society puts it plainly: bone strength increases as we grow and is at its highest around 30 years of age, and after this there is a gradual reduction in bone strength as you get older. Royal Osteoporosis Society, 2026 That happens in both men and women, although in women bone loss speeds up around the menopause.

Clinical reviews describe the same shape. A relatively slow rate of decline in bone mineral density is seen in both sexes beginning at age 40 and continuing throughout adult life. Demontiero, Vidal and Duque, 2012 Nothing hurts. Nothing shows up. The account is simply being drawn down.

For the deposit side of the story — how your peak was set in the first place — see building peak bone mass.

Does turning 40 mean the NHS will check your bone health?

No — and it is worth understanding why, because the reasoning is sound. In July 2026 NICE published NG259, its guideline on osteoporosis risk assessment. It is explicit that osteoporosis is uncommon in men aged under 50 and women aged under 50 who have not experienced menopause, so this group should not be routinely assessed. NICE NG259, 2026

That is not an oversight. It is a judgement about where population-wide assessment finds enough genuine disease to be worth doing. It does mean, though, that in your 40s the responsibility for noticing a reason to look shifts towards you and your GP.

NG259 does name specific triggers for under-50s. Fracture risk assessment is recommended if you have had a previous hip or vertebral fragility fracture, or two or more major osteoporotic fractures. And it should be considered if you have another major risk factor, such as a previous non-hip, non-vertebral fragility fracture, current or frequent use of systemic glucocorticoids, or untreated early menopause or premature ovarian insufficiency. NICE NG259, 2026 If any of those describe you, that is a GP conversation, not a wait-and-see.

Why does menopause status matter more than your age in your 40s?

Because UK guidance is written around menopause, not around birthdays — and menopause can happen well inside this decade. Read NG259 closely and the same phrase keeps recurring: "all people aged 50 and over and women who have experienced menopause". Its recommendation to consider assessment covers all people aged 50 to 74 and women aged under 65 who have experienced menopause with any of a list of risk factors. NICE NG259, 2026

So two women of 47 can sit under completely different rules: the one who has been through menopause is covered by the wider recommendations, the one who has not by the narrow under-50 triggers.

This matters because the timing is genuinely common in this decade. The NHS notes that menopause usually affects women between the ages of 45 and 55, that perimenopause is when periods become irregular, and that early menopause or premature ovarian insufficiency can happen before 45. NHS, 2026 NICE also records that fracture risk is decreased while taking systemic HRT, which is one reason it is worth your GP knowing your full hormonal picture. NICE NG259, 2026

For what happens to bone during the transition itself, see perimenopause and bone health.

Which risk factors should you actually check in your 40s?

The ones nobody connects to bone. NG259 carries a long table of conditions and medicines associated with increased fracture risk. Among those most likely to already be on a 40-something's record: coeliac disease, Crohn's disease and other inflammatory bowel diseases, rheumatoid arthritis and other inflammatory arthropathies such as lupus, hyperthyroidism, hyperparathyroidism, type 1 and type 2 diabetes, chronic liver disease, chronic kidney disease stages 4 and 5, and eating disorders related to low BMI. The medicines named in that table are anticonvulsants, SSRIs, thiazolidinediones, proton pump inhibitors and antiretrovirals; treatment with aromatase inhibitors or androgen deprivation therapy appears there too, under hypogonadism. Systemic glucocorticoids sit outside the table, as a trigger in their own right. NICE NG259, 2026

The practical catch is which list applies to you, and when:

Your situation in your 40s	What NG259 sets out
Under 50, have not been through menopause	Assess if previous hip or vertebral fragility fracture, or 2+ major osteoporotic fractures. Consider if another major risk factor — previous non-hip, non-vertebral fragility fracture; systemic glucocorticoids; untreated early menopause or POI
Under 50 and have been through menopause	Grouped with the post-menopausal recommendations: assess if previous fragility fracture or current or frequent systemic glucocorticoid use; consider assessment where listed risk factors are present
From 50 onwards	The wider list applies: 2+ falls in the last year, first-degree relative's hip fracture (particularly if they were under 80), BMI under 18.5, current smoking, alcohol above 14 units a week, and the conditions and medicines in the guideline's table

Two deserve a flag in this decade specifically, because they so often begin in your 40s: long-term steroid treatment, and an undiagnosed absorption problem such as coeliac disease. Neither is something to self-diagnose — take the list to your GP.

Can you get a fracture risk score in your 40s?

Yes, and 40 is the age at which the best-known tool opens up. NG259 recommends completing a full clinical risk assessment alongside a risk prediction tool to determine the 10-year risk of major osteoporotic fracture, using either FRAX or QFracture for people aged between 40 and 90, and QFracture for people aged 30 to 39. NICE NG259, 2026 The FRAX tool itself accepts ages between 40 and 90. FRAXplus

So a calculation is technically possible before 40 with QFracture — but your 40s are when FRAX, the tool most widely recognised in UK bone clinics, becomes usable for you. NICE also advises using the same tool throughout a person's care, so consistency matters more than which one you start with.

One caution if you run it yourself: NICE pairs the tool with a full clinical risk assessment for a reason. A score is an estimate to be interpreted, not a verdict. Our guide to fracture risk and FRAX explains what the output actually means.

What should you actually do in your 40s?

Load your skeleton, and pay attention to rapid weight loss. On exercise, the Royal Osteoporosis Society is direct: the best way to help your bone strength is to do both impact and strength exercises, because impact sends force through the bone while working muscles pull on it. Royal Osteoporosis Society, 2026 The specifics are in best exercises for bone health.

The newest pressure on 40-something skeletons is deliberate, rapid weight loss, increasingly on GLP-1 medication — which is why protecting your bones on Mounjaro, Wegovy or Ozempic is worth reading before or during treatment rather than after.

Is it worth knowing your bone density in your 40s?

It can be — as a personal reference point, which is a different thing from a clinical screening test. NICE's thresholds are designed to answer a population question: who needs clinical assessment and treatment now. That is not the same as knowing where your own bone health currently sits, and it is not intended to be.

A baseline in your 40s is useful mainly because of what it enables later. A single reading in your 60s tells you a number; a reading in your 60s compared against one from your 40s tells you a direction. Because a REMS assessment uses ultrasound rather than ionising radiation, it can be repeated over the years to build that trend line. It complements clinical care and does not replace it — anything concerning belongs with your GP. When you do reach the next decade, bone density after 50 explains how results are read.

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This article is part of our healthy ageing series. Read next: perimenopause and bone health.