Osteoporosis is not a normal part of aging. Losing some bone density as you get older is normal, but osteoporosis represents a level of bone loss that crosses into disease territory, significantly raising your risk of fractures from minor falls or even everyday activities. The distinction matters because it means osteoporosis is largely preventable, not inevitable.
What’s Normal and What’s Not
Everyone loses bone density after about age 30, when bone mass peaks. This gradual decline is a natural biological process. But there’s a measurable threshold where normal thinning becomes a medical problem. Bone density is measured using a score called a T-score, which compares your bones to those of a healthy young adult. A T-score of -1 or higher is considered healthy. Between -1 and -2.5, you have osteopenia, a milder form of bone loss that signals your bones are thinning faster than expected. At -2.5 or lower, you’ve crossed into osteoporosis.
Think of it like blood pressure. Everyone’s blood pressure rises somewhat with age, but that doesn’t make hypertension “normal.” The same logic applies to bone density. Some decline is expected; a dramatic decline is a disease process that can be slowed, stopped, or even partially reversed.
Why Bones Weaken With Age
Your skeleton is constantly rebuilding itself. Specialized cells break down old bone while others lay down new bone in its place. In younger adults, this cycle stays roughly balanced. As you age, several things tip that balance toward more breakdown and less rebuilding.
The stem cells in your bone marrow that produce bone-building cells gradually shift toward producing fat cells instead. At the same time, the existing bone-building cells become less efficient at their job. Meanwhile, the cells responsible for breaking down bone keep working at full capacity, or even ramp up. The net result is that you lose more bone than you replace with each remodeling cycle.
Oxidative stress, the accumulation of damaging molecules in your cells over a lifetime, also interferes with bone formation pathways. And your immune system becomes less effective at clearing out aging cells that disrupt healthy bone turnover. These are normal aging processes, but how severely they affect your bones depends heavily on your hormones, nutrition, activity level, and genetics.
The Role of Hormones
Estrogen is the single most important hormone for bone health, and not just in women. Estrogen slows the rate of bone breakdown while helping maintain the balance between bone removal and bone formation. When estrogen levels drop, bone-destroying cells multiply and become more active.
For women, the sharp estrogen decline during menopause triggers a period of rapid bone loss that can last 5 to 10 years. This is why osteoporosis is far more common in women: worldwide, it affects roughly one in three women over 50 compared to one in five men. The numbers climb steeply with age. About one in ten women have osteoporosis by age 60, one in five by age 70, two in five by age 80, and two in three by age 90.
Men lose bone more gradually because their testosterone levels decline slowly rather than dropping off a cliff. But testosterone isn’t actually the main player. Research has found that bioavailable estrogen correlates more strongly with bone density changes in men than testosterone does, both during the years when young men are still building bone and during the years when older men are losing it. Estrogen appears to regulate bone breakdown in men, while both estrogen and testosterone contribute to bone formation.
Risk Factors Beyond Age and Sex
Age and hormonal changes set the stage, but they don’t determine the outcome on their own. Several factors push people from normal age-related bone loss into osteoporosis territory. Low body weight, a parental history of hip fracture, smoking, and heavy alcohol use all increase risk. So do dozens of medical conditions and medications that most people wouldn’t associate with their bones.
Long-term use of corticosteroids (commonly prescribed for asthma, arthritis, and autoimmune conditions) can cause bone loss even at low doses. Proton pump inhibitors for acid reflux, certain antidepressants, and some diabetes medications have also been linked to reduced bone density. Chronic inflammatory conditions like rheumatoid arthritis, COPD, and inflammatory bowel disease accelerate bone loss through ongoing immune activity. Thyroid disorders, celiac disease, chronic kidney disease, and diabetes all carry increased osteoporosis risk.
This category, called secondary osteoporosis, accounts for a substantial share of cases. If you’re taking medications or managing chronic conditions that affect bone health, that’s worth a conversation about screening, regardless of your age.
When to Get Screened
The U.S. Preventive Services Task Force recommends bone density screening for all women aged 65 and older. Postmenopausal women younger than 65 should also be screened if they have one or more risk factors, such as low body weight, smoking, excess alcohol use, or a parent who fractured a hip. The task force currently says there isn’t enough evidence to recommend routine screening for men, though men share many of the same risk factors.
Screening is done with a quick, painless scan called a DXA (dual-energy X-ray absorptiometry), which measures bone density at the hip and spine and produces the T-score your doctor uses for diagnosis. The test takes about 10 to 15 minutes and involves very low radiation exposure.
How Osteoporosis Changes Fracture Risk
The practical consequence of osteoporosis is fractures. People with osteoporosis have significantly higher fracture risk than those with osteopenia, particularly at the hip. In one cross-sectional study, about 40% of osteoporosis patients had high hip fracture risk, compared to just 5.6% of those with osteopenia. The vast majority of osteopenia patients (nearly 92%) had low hip fracture risk.
Previous fractures matter enormously. If you’ve already broken a bone from a minor fall, your risk of future fractures jumps considerably, regardless of your current T-score. This is one reason screening catches problems before the first fracture: once the cycle starts, it tends to accelerate.
Protecting Your Bones at Any Age
Because osteoporosis is a disease rather than an inevitability, prevention works. The key strategies are weight-bearing exercise, adequate calcium and vitamin D, and addressing modifiable risk factors like smoking and excess alcohol.
Weight-bearing exercise is particularly effective because bones respond to mechanical stress by becoming denser and stronger. Activities that transmit force through the skeleton, like walking, running, jumping, squats, leg presses, and step-ups, have more bone-building effect than non-weight-bearing activities like swimming or cycling. A combination of impact exercises (jumping, running) and resistance training appears to be especially beneficial. Even whole-body vibration training has shown increases in hip bone density in postmenopausal women.
For nutrition, the National Academy of Medicine recommends 600 IU of vitamin D and 1,000 mg of calcium daily for most adults up to age 70. Women over 51 need 1,200 mg of calcium. Adults over 70 of both sexes should aim for 800 IU of vitamin D and 1,200 mg of calcium. These targets can often be met through diet (dairy, leafy greens, fortified foods, fatty fish) rather than supplements, though supplementation may be appropriate if dietary intake falls short.
The earlier you start building and maintaining bone density, the more you have in reserve as natural age-related losses accumulate. But it’s never too late. Weight-bearing exercise programs improve bone density scores even in elderly people who already have osteoporosis, and they carry the added benefit of improving balance and reducing fall risk.