Osteoporosis: Symptoms, Causes, Tests and Treatment

Osteoporosis is a bone disease in which bones lose density and quality until they become fragile and break easily, often after a simple fall from standing height. It has no symptoms in its early stages, so a broken wrist, hip or spine bone is often the first sign. It is diagnosed with a bone density scan (DXA) and a T-score of -2.5 or lower, or with a typical fragility fracture.

Osteoporosis is common and treatable: about 1 in 5 US women aged 50 and older have it. Medicines cut the risk of new fractures, and blood and urine tests find hidden causes such as low vitamin D, a parathyroid problem, celiac disease or myeloma.

Key takeaways

• 12.6% of US adults aged 50 and older have osteoporosis (19.6% of women, 4.4% of men), and 43.1% have low bone mass.
• It is a "silent disease": height loss, a stooped back or a fracture after a minor fall are often the first signs.
• The USPSTF (2025) recommends screening all women 65 and older and younger postmenopausal women at increased risk.
• A blood and urine work-up (calcium, albumin, phosphate, vitamin D, PTH, kidney function, ALP, blood count and others) looks for secondary causes before treatment.
• Bisphosphonates are first-line; denosumab, romosozumab, teriparatide and abaloparatide are options, and denosumab must never be stopped without a follow-up plan.

What is osteoporosis?

Bone is living tissue: osteoclasts remove old bone while osteoblasts build new bone. MedlinePlus explains that osteoporosis develops when more old bone is reabsorbed than new bone is created. The bones become thinner and their inner honeycomb structure weakens.

The Bone Health and Osteoporosis Foundation (BHOF) clinician's guide calls it the most common metabolic bone disease in the US. It stays silent until a fracture of the spine, hip, wrist or shoulder.

Osteoporosis vs osteopenia

Osteopenia (low bone mass) means bone density is below that of a healthy young adult, but not low enough for osteoporosis. In the CDC survey, 51.5% of women and 33.5% of men aged 50 and older had it. It raises fracture risk, and some people with osteopenia and a high FRAX score need treatment.

Osteoporosis is not osteoarthritis, a joint disease that causes pain and stiffness, although both are common with age.

Who gets osteoporosis?

Women are affected much more often than men. CDC data (NHANES 2017-2018) show osteoporosis in 13.1% of women aged 50 to 64 and 27.1% of women 65 and older, versus 3.3% and 5.7% of men. Among women, it rose from 14.0% in 2007-2008 to 19.6%.

BHOF estimates that about 54 million Americans have osteoporosis or low bone mass, and that about one in two women and up to one in four men aged 50 and older will break a bone because of osteoporosis.

Osteoporosis causes and risk factors

Primary osteoporosis is linked to aging and menopause; secondary osteoporosis is caused by another disease or a medicine.

Primary causes

• Menopause: lower estrogen speeds up bone loss. Our guide to menopause symptoms and stages explains this transition.
• Aging, and in men, the slow fall of testosterone with age.
• Family history of osteoporosis or hip fracture.
• Low body weight, smoking and heavy alcohol use.
• Long periods without menstrual periods, and eating disorders such as anorexia nervosa.
• Not getting enough calcium and vitamin D, or poor absorption, for example after gastric bypass surgery.

Secondary causes

• Glucocorticoids (steroid pills such as prednisone): BHOF notes that 5 mg a day or more for three months or longer can increase bone loss.
• Inflammatory diseases such as Crohn's disease and rheumatoid arthritis.
• Hormonal disorders, including excess cortisol in Cushing's syndrome, low testosterone and parathyroid disease.
• Digestive disorders that block absorption, such as celiac disease.
• Blood disorders and some cancers, including multiple myeloma.
• Certain antidepressants and acid-reducing drugs, mainly at high doses or long term; never stop a medicine without talking to your doctor.

Researchers are also looking at other nutrients, such as vitamin B12 and fracture risk after 50.

Osteoporosis symptoms

Early osteoporosis has no symptoms; many people learn they have it only after a fracture. Signs include:

• a fracture after a minor fall or bump (fragility fracture);
• sudden back pain, sometimes without any injury, from a spine compression fracture;
• loss of height: MedlinePlus notes it can reach as much as 6 inches (15 cm) over time;
• a stooped posture or a curved upper back (sometimes called a dowager's hump).

One fracture is a warning. The BHOF guide explains that a vertebral fracture carries a 5-fold higher risk of another vertebral fracture and a 2- to 3-fold higher risk of fractures at other sites, especially in the year after the first fracture.

Osteoporosis diagnosis: bone density test and FRAX

Who should get a bone density test?

In January 2025, the US Preventive Services Task Force (USPSTF) recommended screening for osteoporosis in all women 65 and older, and in postmenopausal women younger than 65 who are at increased risk based on a clinical risk assessment (both grade B). It found the evidence insufficient to recommend for or against screening in men (I statement).

BHOF also suggests testing men 70 and older, younger adults over 50 with risk factors, anyone with a fracture after 50, and people on glucocorticoids.

How the DXA scan works

Dual-energy x-ray absorptiometry (DXA or DEXA) is a quick, painless, low-radiation x-ray of the hip and lower spine. MedlinePlus notes that it diagnoses bone loss, predicts fracture risk and monitors treatment, usually repeated every 2 years or longer. It can also look for silent spine fractures (vertebral fracture assessment).

T-score and Z-score: reading your bone density results

The T-score compares your bone density with that of a healthy young adult. The Z-score compares it with people of your age and sex. For postmenopausal women and men aged 50 and older, the T-score is used:

Premenopausal women, men under 50 and children cannot be diagnosed on bone density alone. Once made, the diagnosis stays even if a later T-score rises above -2.5.

FRAX: your 10-year fracture risk

FRAX is a free online calculator that combines clinical risk factors (age, sex, weight, previous fracture, parental hip fracture, smoking, alcohol, glucocorticoids, rheumatoid arthritis) with or without femoral neck bone density. It estimates your 10-year probability of a hip fracture and of a major osteoporotic fracture (spine, forearm, hip or shoulder). In the US, BHOF suggests treatment for people with osteopenia when the 10-year hip fracture risk is 3% or more or the major osteoporotic fracture risk is 20% or more.

Osteoporosis blood test: the lab work-up for secondary causes

No blood test diagnoses osteoporosis: bone density is measured by DXA. But blood and urine tests matter, because a hidden cause can make treatment fail or some drugs unsafe. The BHOF guide lists a core panel and extra tests for selected patients. Our article on the calcium and bone mineral panel shows how these results fit together.

Core tests

• A complete blood count (CBC), to look for anemia or a blood disorder.
• Serum calcium, corrected for albumin: a high calcium suggests a parathyroid problem; a low calcium must be corrected before some drugs.
• Phosphorus and magnesium.
• Kidney function: creatinine and eGFR, which guide the choice of drug.
• Liver tests, including alkaline phosphatase (ALP), which can rise with bone disease, a healing fracture, osteomalacia or Paget disease of bone.
• 25-hydroxy vitamin D.
• Parathyroid hormone (PTH).
• In men aged 50 to 69: total testosterone and gonadotropins (LH, FSH).
• A 24-hour urine collection for calcium and creatinine, to detect calcium loss through the kidneys or poor absorption.

Tests for selected patients

• Serum protein electrophoresis (SPEP), immunofixation and free light chains, to rule out multiple myeloma, especially with a spine fracture, anemia or high calcium.
• TSH, with or without free T4, to look for thyroid overactivity.
• Tissue transglutaminase antibodies with total IgA, to screen for celiac disease.
• Iron and ferritin, prolactin, tryptase, and urine or salivary cortisol when the history suggests a specific cause.

Reference values: lab tests in an osteoporosis work-up

Typical adult ranges in US and SI units; always compare with the range on your own report.

How to read your results

• High calcium with a high or normal PTH points to primary hyperparathyroidism. Read our guides to the calcium blood test and PTH.
• Low vitamin D with a high PTH and a high ALP suggests vitamin D deficiency or osteomalacia. BHOF advises aiming for at least 30 ng/mL (75 nmol/L) and not above 50 ng/mL (125 nmol/L).
• A low eGFR matters before denosumab or bisphosphonates; in advanced kidney disease, a specialist assessment is needed.
• A monoclonal protein on SPEP or a positive celiac test needs further tests first.

Bone turnover markers: CTX and P1NP

Serum CTX reflects bone breakdown and P1NP reflects bone formation. They are not FDA-approved to diagnose osteoporosis, but the BHOF guide uses them to check that treatment is taken and working (CTX for antiresorptive drugs, P1NP for bone-building drugs). A CTX drop of about 40% is the smallest real change.

Osteoporosis treatment

Treatment aims to prevent fractures. The American College of Physicians (ACP) living guideline (2023) recommends bisphosphonates as first-line treatment for postmenopausal women with osteoporosis (strong recommendation) and suggests them for men too. Denosumab is the second-line choice for people who cannot take bisphosphonates. Romosozumab or teriparatide, followed by a bisphosphonate, are suggested for women at very high fracture risk.

Bisphosphonates (alendronate, risedronate, ibandronate, zoledronic acid)

These drugs slow the cells that break down bone. They come as tablets or as a yearly IV infusion of zoledronic acid. In trials, alendronate reduced spine and hip fractures by about half over 3 years in women with a prior spine fracture or osteoporosis at the hip. After 5 years of tablets or 3 years of IV treatment, doctors reassess; people no longer at high risk may take a drug holiday.

Denosumab, the twice-yearly injection

Denosumab (Prolia) is an antibody that blocks RANKL, the signal that activates bone-resorbing cells; ChEMBL lists it as a TNF ligand superfamily member 11 (RANKL) inhibitor. It is injected under the skin every 6 months. In the FREEDOM trial, it reduced spine fractures by about 68%, hip fractures by about 40% and non-spine fractures by about 20%, with benefits maintained in extensions up to 5 years and beyond.

Key safety rule: never stop or delay denosumab without a plan. Bone loss is rapid after the last dose, and a rebound can cause multiple spine fractures. Doctors usually follow it with a bisphosphonate.

Bone-building drugs: teriparatide, abaloparatide and romosozumab

• Teriparatide and abaloparatide are daily injections that act on the parathyroid hormone receptor and stimulate new bone. They are usually given for 2 years. Teriparatide reduced spine fractures by 65-77% and abaloparatide by about 86% in their main trials.
• Romosozumab (Evenity) blocks sclerostin, a brake on bone formation. It is given monthly for 12 months. In the ARCH trial, it led to 48% fewer new spine fractures and 38% fewer hip fractures than alendronate. It carries a boxed warning for heart attack, stroke and cardiovascular death and is not used after a heart attack or stroke in the past year.

Bone-building drugs are always followed by an antiresorptive drug to keep the gain.

Raloxifene and hormone therapy

Raloxifene, a selective estrogen receptor modulator, reduces spine fractures but not other fractures. Menopausal hormone therapy also prevents fractures: in the Women's Health Initiative, 5 years of estrogen plus progestin reduced hip and clinical spine fractures by 34%. When fracture prevention is the only goal, the FDA advises non-estrogen treatments first.

Side effects in perspective

Osteonecrosis of the jaw and atypical femur fractures are rare. For oral bisphosphonates, BHOF estimates the jaw problem at 1 in 10,000 to 1 in 100,000 patients. For most people with osteoporosis, the risk of a fracture without treatment is far greater.

Osteoporosis prevention: calcium, vitamin D, exercise and falls

• Calcium: BHOF advises a total intake (food plus supplements) of 1,000 mg a day for men aged 50 to 70, and 1,200 mg for women 51 and older and men 71 and older.
• Vitamin D: 800 to 1,000 units a day is a typical supplement for adults over 50, with more if a blood test shows deficiency.
• Exercise: weight-bearing activity, strength and balance training; MedlinePlus suggests walking 30 minutes three times a week. No smoking, limited alcohol.
• Fall prevention: the USPSTF (2024) recommends exercise programs to prevent falls in adults 65 and older at increased risk. Remove trip hazards, use grab bars, check your vision and review sedating medicines; the CDC STEADI program helps clinicians assess fall risk.

Osteoporosis in men and glucocorticoid-induced osteoporosis

Men break bones less often than women, and the evidence on screening and treatment in men is more limited. The BHOF guide suggests a bone density test for all men 70 and older and for men 50 to 69 with risk factors. Their work-up includes testosterone; read about low testosterone in men. Alendronate, risedronate, zoledronic acid and denosumab are used in men.

The 2022 American College of Rheumatology guideline applies to anyone taking 2.5 mg or more of prednisone a day for more than 3 months. It recommends assessing fracture risk as soon as possible after starting, with bone density, a spine image and FRAX from age 40, and treating everyone at medium, high or very high risk.

When to see a doctor

See your doctor if you are a woman 65 or older never screened, postmenopausal with risk factors, starting long-term steroids, losing height, or if you broke a bone after a minor fall.

Call 911 or go to the emergency room right away if you:

• fall and cannot get up, cannot put weight on a leg, or have severe hip or groin pain;
• have sudden, severe back pain with weakness, numbness or loss of bladder or bowel control;
• develop muscle spasms (tetany) or trouble breathing in the weeks after a denosumab injection, especially if you have kidney failure or are on dialysis: very low calcium can cause these symptoms.

Latest scientific advances in osteoporosis

USPSTF 2025: screening for more women, and an open question for men

The January 2025 USPSTF statement in JAMA confirmed screening for women 65 and older and for younger postmenopausal women at increased risk, estimated with a clinical risk tool before ordering DXA. A 2025 cluster randomized trial in 39 Veterans Affairs primary care teams (3,112 men aged 65 to 85, NCT04079868) showed what organized screening can do: 49.2% of men offered a remote bone health service were screened versus 2.3% with usual care, and more than half of those screened had osteopenia or osteoporosis.

A shorter course of romosozumab

In the LIDA trial (Lancet Diabetes and Endocrinology, 2026, NCT05010590), 50 postmenopausal women at high risk received either 3 months of romosozumab followed by denosumab, or the standard 12 months of romosozumab. Total hip bone density rose by 5.7% versus 6.0%, which met the non-inferiority goal. Fracture outcomes still need larger studies.

Denosumab and kidney failure: a safety signal

An FDA study in JAMA (2024) of women 65 and older on dialysis found severe hypocalcemia (corrected calcium below 7.5 mg/dL, or 1.88 mmol/L) within 12 weeks in 41.1% of those starting denosumab versus 2.0% with oral bisphosphonates. This is why eGFR and calcium are checked before treatment.

How to stop denosumab safely

Several trials are testing the best follow-up treatment. ZOLARMAB2 (NCT05655013, 200 women, results expected in 2027) compares zoledronic acid with placebo after denosumab. A French trial (NCT06767150, recruiting) gives a second zoledronic acid infusion when CTX rises above 300 pg/mL, using the bone breakdown marker to time treatment. Meanwhile, the ACP keeps its guideline "living", with update alerts published in 2025 and 2026.

Which tests can help?

Lab tests complete the DXA scan:

• calcium, albumin, phosphorus and magnesium;
• 25-OH vitamin D and PTH;
• creatinine and eGFR, plus liver tests and ALP;
• a complete blood count;
• TSH, celiac antibodies, SPEP and, in men, testosterone when indicated;
• 24-hour urine calcium and creatinine;
• CTX and P1NP to check that treatment works.

Glossary

• DXA (DEXA): a low-dose x-ray that measures bone mineral density at the hip and spine.
• T-score: your bone density compared with a healthy young adult; -2.5 or lower means osteoporosis.
• Osteopenia: low bone mass, a T-score between -1.0 and -2.5.
• Antiresorptive: a drug that slows bone breakdown (bisphosphonates, denosumab, raloxifene).
• Anabolic: a drug that builds new bone (teriparatide, abaloparatide, romosozumab).
• CTX and P1NP: blood markers of bone breakdown and bone formation.

Frequently asked questions

How to build bone density?

Combine strength and weight-bearing exercise with enough calcium and vitamin D. In the LIFTMOR trial, 8 months of supervised high-intensity resistance and impact training raised lumbar spine density by 2.9% in women with low bone mass, while it fell by 1.2% with home exercise. If you have osteoporosis, medicines add much larger and proven benefits.

What are the treatment options for osteoporosis?

Bisphosphonates come first; other options are denosumab, teriparatide, abaloparatide, romosozumab, raloxifene and, for some women, hormone therapy, always with calcium, vitamin D, exercise and fall prevention.

What is osteopenia?

Osteopenia is low bone mass: a T-score between -1.0 and -2.5. It is not osteoporosis, but it raises fracture risk. Doctors use FRAX to decide whether treatment is needed; in the US, a 10-year hip fracture risk of 3% or more, or a major fracture risk of 20% or more, usually leads to treatment.

Can osteoporosis be reversed without medication?

Not fully. Exercise, diet and vitamin D can slow bone loss and modestly increase density, as in the LIFTMOR trial, and they improve balance and strength. But in established osteoporosis, only medicines have been shown to lower fracture risk substantially. The BHOF guide notes that drugs treat but do not cure the disease.

Is osteoporosis deadly?

Osteoporosis itself is not fatal, but its fractures can be: the USPSTF links them with loss of independence and death. Treatment and fall prevention reduce this risk.

What is the osteoporosis treatment injection?

Several treatments are injections: denosumab every 6 months, zoledronic acid as a yearly IV infusion, romosozumab monthly for one year, and teriparatide or abaloparatide daily for up to 2 years.

Sources

• USPSTF, Nicholson WK et al. — Screening for Osteoporosis to Prevent Fractures — JAMA, 2025 — doi.org
• Qaseem A et al. — Pharmacologic Treatment of Primary Osteoporosis: ACP Living Guideline — Ann Intern Med, 2023 — doi.org
• Qaseem A et al. — ACP osteoporosis guideline, Update Alert 1 — Ann Intern Med, 2025 — doi.org
• Qaseem A et al. — ACP osteoporosis guideline, Update Alert 2 — Ann Intern Med, 2026 — doi.org
• LeBoff MS et al. — The clinician's guide to prevention and treatment of osteoporosis (BHOF) — Osteoporos Int, 2022 — doi.org
• Humphrey MB et al. — 2022 ACR Guideline on Glucocorticoid-Induced Osteoporosis — Arthritis Rheumatol, 2023 — doi.org
• Tsourdi E et al. — Discontinuation of denosumab therapy: ECTS position statement — Bone, 2017 — doi.org
• Bird ST et al. — Severe Hypocalcemia With Denosumab in Dialysis Patients — JAMA, 2024 — doi.org
• Leder BZ et al. — 3 vs 12 months of romosozumab (LIDA) — Lancet Diabetes Endocrinol, 2026 — doi.org
• Colón-Emeric C et al. — Remote Bone Health Service for Screening in Men — JAMA Intern Med, 2025 — doi.org
• Watson SL et al. — High-Intensity Resistance and Impact Training (LIFTMOR) — J Bone Miner Res, 2018 — doi.org
• USPSTF, Nicholson WK et al. — Interventions to Prevent Falls in Older Adults — JAMA, 2024 — doi.org
• Aarhus University Hospital — Zoledronate after denosumab (ZOLARMAB2, NCT05655013) — ClinicalTrials.gov — clinicaltrials.gov
• University Hospital, Toulouse — Zoledronic acid after stopping denosumab (NCT06767150) — ClinicalTrials.gov — clinicaltrials.gov
• Sarafrazi N et al. — Osteoporosis or Low Bone Mass in Older Adults, 2017-2018 — NCHS Data Brief 405, 2021 — cdc.gov
• Bone Health and Osteoporosis Foundation — What Is Osteoporosis and What Causes It? — BHOF — bonehealthandosteoporosis.org
• MedlinePlus — Osteoporosis — Medical Encyclopedia — medlineplus.gov
• MedlinePlus — Calcium blood test — Medical Encyclopedia — medlineplus.gov
• MedlinePlus — Phosphorus blood test — Medical Encyclopedia — medlineplus.gov
• MedlinePlus — Albumin blood test — Medical Encyclopedia — medlineplus.gov
• MedlinePlus — ALP blood test — Medical Encyclopedia — medlineplus.gov
• MedlinePlus — Parathyroid hormone (PTH) blood test — Medical Encyclopedia — medlineplus.gov
• MedlinePlus — 25-hydroxy vitamin D test — Medical Encyclopedia — medlineplus.gov
• MedlinePlus — Calcium urine test — Medical Encyclopedia — medlineplus.gov
• MedlinePlus — TSH test — Medical Encyclopedia — medlineplus.gov
• MedlinePlus — Testosterone — Medical Encyclopedia — medlineplus.gov
• MedlinePlus — Glomerular Filtration Rate (GFR) Test — Lab Tests — medlineplus.gov
• CDC — STEADI: Older Adult Fall Prevention — CDC — cdc.gov
• FRAX — Fracture risk assessment tool — FRAXplus — fraxplus.org
• Yoshida K et al. — Severe hypocalcemia after denosumab in a dialysis patient — Perit Dial Int, 2025 — doi.org
• EMBL-EBI — ChEMBL drug mechanisms — ChEMBL — ebi.ac.uk

Further reading

• Corrected calcium: meaning and how it is used
• Magnesium levels in blood: how to read results
• Kidney function panel: how to read it
• Male hormone panel: what it measures
• tTG-IgA test: when celiac skips the biopsy
• Estradiol levels: what your blood test means

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