Osteoporosis is a condition where bones become so weak and porous that they fracture from minor falls, bumps, or even routine movements like bending over. It develops silently over years, rarely causing symptoms until a bone actually breaks. Roughly 8.9 million fractures worldwide each year are attributed to osteoporosis, and the condition contributed to nearly 460,000 deaths globally in 2021.
How Bones Weaken Over Time
Your skeleton is not a static structure. It constantly rebuilds itself through a process called remodeling. Specialized cells called osteoclasts break down old bone tissue by releasing enzymes and acids that dissolve the bone matrix. Then a second type of cell, osteoblasts, moves in and fills the gaps with fresh collagen and minerals. In a healthy adult, these two processes stay roughly in balance.
Osteoporosis develops when bone breakdown outpaces bone rebuilding. This imbalance accelerates with age in everyone, but it’s especially pronounced after menopause. Estrogen normally helps regulate the remodeling cycle, so when estrogen levels drop sharply, bone loss speeds up. Men with low estrogen levels experience the same acceleration. Over time, the internal structure of the bone becomes thinner and more porous, like a sponge with increasingly large holes, until the bone can no longer handle everyday mechanical stress.
Why It’s Called a “Silent Disease”
Osteoporosis causes no pain and no visible changes until something breaks. Many people first learn they have it after fracturing a bone from a fall that wouldn’t have caused injury a decade earlier. Some discover it even more dramatically: vertebrae in the spine can compress and collapse under normal body weight, causing sudden back pain, loss of height, and a stooped posture. These compression fractures sometimes happen without any obvious injury at all.
Where Fractures Happen Most
The fractures most strongly linked to osteoporosis occur in three areas: the vertebrae (bones of the spine), the femoral neck (the upper part of the thighbone near the hip), and the distal radius (the wrist end of the forearm bone). Pelvic fractures and upper arm fractures also rank high on the list.
Hip fractures are the most dangerous. Among patients 65 and older who undergo hip surgery after a fracture, roughly 27% die within one year. The fracture itself isn’t usually the direct cause of death. Instead, the immobility, surgical stress, and complications that follow are what prove fatal. Circulatory diseases account for about 44% of these deaths, followed by dementia-related decline and respiratory disease. Even for survivors, a hip fracture often marks the end of independent living.
Who Is Most at Risk
Women account for 75% to 80% of osteoporosis-related fractures, largely because of the estrogen drop after menopause. But men are far from immune. When men do fracture a hip, they actually have higher death rates than women.
Beyond age and sex, several factors raise your risk significantly:
- Long-term steroid use. Glucocorticoids (commonly prescribed for asthma, arthritis, and autoimmune conditions) are one of the most common medication-related causes of osteoporosis. They interfere with bone-building cells and speed up bone loss.
- Other medications. Cancer therapies that suppress hormones, anti-seizure drugs, blood thinners like heparin, and thyroid hormone replacement at high doses all contribute to bone loss.
- Medical conditions. Overactive thyroid or parathyroid glands, type 1 diabetes, inflammatory bowel disease, rheumatoid arthritis, kidney failure, and Cushing’s syndrome each increase risk independently.
- Lifestyle factors. Smoking, heavy alcohol use, physical inactivity, and a diet low in calcium and high in sodium all weaken bones over time.
- Bariatric surgery. Weight-loss surgery has emerged as an increasingly recognized cause of secondary osteoporosis, partly because it reduces nutrient absorption.
How Osteoporosis Is Diagnosed
A bone density scan, often called a DXA scan, measures how much mineral is packed into a small section of bone, typically at the hip and spine. The result is reported as a T-score, which compares your bone density to that of a healthy 30-year-old adult.
- T-score of -1 or higher: healthy bone density
- T-score between -1 and -2.5: osteopenia (bone density is lower than normal but not yet osteoporosis)
- T-score of -2.5 or lower: osteoporosis
The U.S. Preventive Services Task Force recommends routine bone density screening for all women aged 65 and older. Postmenopausal women younger than 65 should also be screened if they have risk factors such as low body weight, a family history of fractures, smoking, or steroid use. For men, there is currently no formal screening recommendation because the evidence on benefits and harms hasn’t been established clearly enough, though many doctors order scans for men with known risk factors.
Calcium and Vitamin D Needs
Calcium and vitamin D form the nutritional foundation for bone health. Calcium provides the raw building material, and vitamin D enables your gut to absorb it. Without enough vitamin D, you can take all the calcium supplements you want and still lose bone.
Women over 50 and men over 70 need 1,200 mg of calcium daily from food and supplements combined. Good dietary sources include dairy products, fortified plant milks, canned sardines and salmon (with bones), leafy greens like kale and bok choy, and fortified cereals. For vitamin D, adults over 50 should aim for 800 to 1,000 IU daily, with a safe upper limit of 4,000 IU. Many people in northern climates or those who spend little time outdoors are deficient without realizing it.
How Osteoporosis Is Treated
Treatment falls into two broad categories: medications that slow bone loss and medications that actively build new bone.
The most commonly prescribed drugs are bisphosphonates. These attach to bone surfaces at the spots where breakdown is happening fastest, kill off the cells responsible for dissolving bone, and slow resorption. One notable feature of bisphosphonates is that they bind to bone mineral and continue releasing slowly for years after you stop taking them, providing some lingering protection. They’re available as daily or weekly pills, or as infusions given once a year.
Another option works differently: it’s a biologic injection given every six months that blocks a key signal osteoclasts need to form and survive. This approach reduces bone breakdown effectively, but unlike bisphosphonates, its protective effect reverses quickly once you stop treatment. Missing doses or discontinuing without a transition plan can lead to rapid bone loss and even rebound fractures, particularly in the spine.
For people with severe osteoporosis or those who continue fracturing despite other treatments, bone-building drugs offer a different approach. These are daily injections that stimulate osteoblasts to form new bone faster than it’s being broken down, producing a net gain in bone density. They’re typically used for a limited period (one to two years) and followed by a medication that maintains the gains.
Hormone therapy with estrogen remains effective for preventing bone loss in postmenopausal women, though it’s used less often today because of concerns about cardiovascular and cancer risks with long-term use. A related class of drugs mimics estrogen’s bone-protective effects without some of its risks in other tissues.
Exercise and Fall Prevention
Weight-bearing exercise, where your bones work against gravity, stimulates the remodeling cycle in favor of building. Walking, jogging, dancing, stair climbing, and resistance training all count. Swimming and cycling, while great for cardiovascular health, don’t load the skeleton enough to meaningfully strengthen bone.
Equally important is preventing falls. Most osteoporotic fractures result from a fall, and for older adults, simple environmental changes make a real difference: removing loose rugs, improving lighting, installing grab bars in bathrooms, and wearing shoes with good traction. Balance training through exercises like tai chi has strong evidence for reducing fall risk in older adults. Strengthening the muscles around the hips and legs helps absorb impact and protect vulnerable bones if a fall does happen.