Osteoporosis is a condition where bones become so weak and brittle that they break much more easily than they should. It happens when the body loses bone density faster than it can rebuild it, leaving bones porous and fragile. Nearly 19% of women and about 4% of men over age 50 in the United States have osteoporosis in the hip or spine.
What Happens Inside Your Bones
Your bones are not static structures. They’re constantly being broken down and rebuilt in a process called remodeling. Two types of cells drive this cycle: one type removes old bone tissue, and another type fills in the gaps with fresh bone. In healthy adults, these two processes stay roughly in balance, so bone stays strong.
The breakdown phase is fast. The rebuilding phase is slow. This means that anytime the cycle speeds up or tips out of balance, you tend to lose more bone than you gain. In osteoporosis, this imbalance runs unchecked for years, gradually hollowing out the internal structure of bones until they become fragile enough to fracture from a minor fall or, in severe cases, just bending over.
Why It’s Called a “Silent Disease”
Osteoporosis produces no symptoms in its early stages. You can’t feel your bones thinning. Most people don’t know they have it until a bone breaks unexpectedly. The fracture itself is often the first sign.
As the condition progresses, some physical changes may appear. Small fractures in the vertebrae (the bones stacked in your spine) can happen without obvious injury. These compression fractures cause back pain, a gradual loss of height over time, and a stooped or hunched posture. A bone that breaks from something as minor as a cough or a stumble is a hallmark of osteoporosis.
Where Fractures Happen Most
The spine, hip, and wrist are the most common sites for osteoporotic fractures, followed by the upper arm. Hip and spine fractures are considered the most serious. A hip fracture often requires surgery and months of recovery, and it can permanently limit mobility in older adults. Spinal compression fractures accumulate over time, each one stealing a bit more height and curving the upper back forward.
What Causes Bone Loss
The single biggest driver is the drop in estrogen that comes with menopause. Estrogen helps keep bone-removing cells in check by triggering their natural death cycle. When estrogen levels fall, those cells live longer and work harder, accelerating bone breakdown. This is why women lose bone rapidly in the five to seven years after menopause and why women develop osteoporosis at roughly four times the rate men do.
Age plays a role for everyone. After about age 30, bone rebuilding can no longer fully keep pace with bone removal, and total bone mass slowly declines. Other factors that raise your risk include a family history of osteoporosis, a small or thin body frame, smoking, heavy alcohol use, and a sedentary lifestyle.
Certain medications also weaken bones over time. Long-term use of corticosteroids (commonly prescribed for asthma, arthritis, and autoimmune conditions) is one of the most well-known culprits. Some acid-reflux medications, certain antidepressants, and drugs used to treat epilepsy or hormone-sensitive breast cancer can also contribute to bone loss.
How It’s Diagnosed
A bone density scan, often called a DEXA scan, measures how dense your bones are compared to a healthy 30-year-old adult. The result is expressed as a T-score:
- T-score of -1 or higher: healthy bone density
- T-score between -1 and -2.5: osteopenia, a milder form of bone loss that can progress to osteoporosis
- T-score of -2.5 or lower: osteoporosis
The U.S. Preventive Services Task Force recommends routine screening for all women at age 65 and older. Postmenopausal women younger than 65 should be screened if they have risk factors such as low body weight, smoking, a family history of hip fracture, or long-term corticosteroid use. For men, there’s no standard screening recommendation yet. Doctors use their own judgment based on individual risk.
Protecting Your Bones With Exercise
Two categories of exercise matter most for bone density: weight-bearing exercise and resistance training. Weight-bearing exercise is anything done on your feet where your legs support your body. For younger and more active adults, running, dancing, jumping rope, and aerobics all create the kind of impact that stimulates bone growth. For people over 60, brisk walking, tennis, and fitness classes provide the same benefit at lower intensity.
Resistance training works differently. When muscles pull hard against bone through activities like weightlifting, push-ups, or using gym machines, the mechanical stress signals the bone to reinforce itself. Adults of all ages benefit from working the major muscle groups at least two days a week.
Calcium and Vitamin D Needs
Calcium is the primary mineral in bone tissue, and vitamin D helps your body absorb it. Adults ages 19 to 50 need about 1,000 mg of calcium per day. After age 50, that target rises to 1,000 to 1,200 mg per day. Most adults need 600 IU of vitamin D daily, though some doctors recommend more for people who are already deficient or at high risk for osteoporosis.
Dairy products, leafy greens, fortified cereals, and canned fish with soft bones (like sardines) are all good calcium sources. Vitamin D comes from sunlight exposure, fatty fish, egg yolks, and fortified foods. When diet alone falls short, supplements can help fill the gap, but exceeding 2,000 to 2,500 mg of calcium per day from all sources combined is not recommended and can cause other health problems.