Bone formation continues at a pace faster than resorption (bone loss) until peak bone mass (maximum bone density and strength) is reached around age 30. After age 30, bone resorption slowly begins to exceed bone formation.

Something as harmless as coughing can cause a rib fracture, but the most common cause of fractures is a fall. The most common sites for fractures are the back, wrist, and hip. A fall or break can result in a trip to the hospital, surgery, and possibly a long-term disabling condition. Osteoporosis is the cause of 1.5 million fractures each year, including more than 300,000 hip fractures. These fractures may put an end to independent living for as many as one in four people with a broken hip. It's important to prevent falls. Some things you can do include using glasses or a hearing aid, if needed; asking your doctor if any of the drugs you are taking may make you dizzy or unsteady on your feet; using a cane or walker if your walking is unsteady; wearing rubber-soled and low-heeled shoes; making sure all the rugs and carpeting in your house are firmly attached to the floor; keeping your rooms well lit and the floor free of clutter; and using nightlights.

White and Asian women are most at risk. African-American and Latino women have a lower but significant risk.

After age 30, bone loss begins to occur, but slowly. In women, the rate of loss increases for several years after menopause, then slows again, but continues. As men age, they don't have the same kinds of striking hormone losses as women do in midlife. In men, the drop occurs more slowly. But, by age 65 or 70, men and women are losing bone at the same rate. Men have only a fourth as many hip fractures as women, but men over age 75 are three times more likely to die after a hip fracture than are women.

According to the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), excess alcohol affects bone health by interfering with the balance of calcium. It increases parathyroid hormone levels, which reduce the body’s calcium reserves, and it interferes with the production of vitamin D, a vitamin essential for calcium absorption. NIAMS says chronic heavy drinking can cause hormone deficiencies in men and women. Men with alcoholism tend to produce less testosterone, a hormone linked to the production of the cells that stimulate bone formation. In women, chronic alcohol exposure often causes irregular menstrual cycles, which reduces estrogen levels, increasing osteoporosis risk. Also, cortisol levels tend to be elevated in people with alcoholism. Cortisol is a hormone known to decrease bone formation and increase bone breakdown. Genetics play an important role in predicting the condition's likelihood; people whose parents have a history of fractures also seem to have reduced bone mass and may also be at risk for fractures. The relationship between smoking and osteoporosis is complicated. Smokers may have a decrease in bone density because of smoking itself or because of other risk factors common to smokers. For example, many smokers are thin, drink more alcohol, may be less physically active, and have poor diets. Women who smoke also tend to have an earlier menopause than nonsmokers. Smoking causes a woman’s body to make less estrogen, which protects the bones. Men who smoke are two or three times more likely to develop osteoporosis.

Losing height or having a bone break easily is often the first sign of osteoporosis. "Bone density" is a term that describes how solid your bones are. Ordinary X-rays do not show bone loss until a large amount of bone density is gone. The most precise way to measure bone density is by a DEXA-scan (dual-energy X-ray absorptiometry). A DEXA-scan is done on the whole body and is a painless, low-dose X-ray. Common sites for the scan are the spine, hip, wrist, middle finger, heel, and shinbone. Ask your doctor about this test if you think you are at risk for osteoporosis or if you are a woman around the age of menopause or older. The DEXA-scan can show whether you are at risk for a fracture. If you have already broken a bone and your doctor thinks you might have osteoporosis, the test can confirm the diagnosis. If more than one test is done at least a year apart, your doctor can compare the test results over time. Then he or she can see if the treatment has succeeded in slowing your bone loss.

The compression shortens the body's height, resulting in the curved back.

Weight-bearing exercise is the only kind that builds density. Try walking, playing tennis, jogging, or dancing three times a week.

Osteoporosis is preventable. A diet that is rich in calcium and vitamin D and a lifestyle that includes regular weight-bearing exercise are the best ways to prevent weakened bones later in later life. Here's what you need to know: Getting enough calcium all through your life helps to build and keep bones strong. People ages 31 to 50 should get 1,000 mg of calcium each day. People over 50 should get 1,200 mg daily. Your body uses vitamin D to absorb calcium. Being out in the sun for 10 to 15 minutes a day, without sunscreen, two days a week helps most people’s bodies make enough vitamin D. You can also get vitamin D from eggs, fatty fish, and cereal and milk fortified with vitamin D, as well as from supplements. Exercise makes bones and muscles stronger and helps prevent bone loss. It also helps you stay active and mobile. Weight-bearing exercises, done three to four times a week, are best: walking, jogging, playing tennis, dancing.

Treatment of osteoporosis aims to stop bone loss and rebuild bone. Along with making lifestyle changes, several medications are available. Some will slow your rate of bone loss, and others will actually rebuild bone. These include: estrogen, raloxifene, alendronate, risedronate, denosumab, and calcitonin. Doctors sometimes prescribe estrogen to replace the hormones lost during menopause, to slow the rate of bone loss, and to increase bone mass in the spine and hip. Supplemental estrogen and progesterone may cause the risk for other health conditions to increase. Raloxifene, approved to prevent osteoporosis, is known as a SERM (selective estrogen receptor modulator). Like estrogen, this SERM prevents bone loss. Alendronate and risedronate are bisphosphonates, drugs that slow the breakdown of bone and may even increase bone density. Calcitonin is a naturally occurring hormone that increases bone mass in the spine and may lessen the pain of fractures there. Denosumab is an injectable, twice-yearly treatment for osteoporosis that is given to women who are at severe risk for osteoporotic fractures.