Causes of Osteoporosis

Medically Reviewed by Melinda Ratini, MS, DO on July 30, 2021
4 min read

Are you searching for what causes osteoporosis? You may be surprised to learn that many factors contribute to the condition. For instance, a decrease in estrogen at menopause is one cause. There is also a genetic component. If your mother or grandmother had osteoporosis, the chances are higher that you will develop it, too.

Eating a diet that's low in calcium, getting little exercise, and smoking cigarettes can also increase your chances of getting osteoporosis. It's important to know all you can about what causes osteoporosis. Then you can take preventive steps to stop this disease and lower your risk of bone fractures.

In childhood and adolescence, the body constantly breaks down old bone and rebuilds new bone. It does this through a process called "remodeling." During this time, the body builds more bone than it removes, and so bones grow and get stronger.

You often hear how important it is for women to get enough calcium. But it's just as important -- maybe even more important -- that kids and teens get ample bone-boosting calcium. It's also important for them to exercise daily to build strong bones.

For most women, the total amount of bone peaks somewhere between ages 25 and 30. It may peak even sooner for some women, depending on their risk factors for osteoporosis.

When the total amount of bone peaks, the tide turns. At some point, usually around age 35, women start to lose bone.

While some bone is lost each year, the rate of bone loss increases dramatically in the 5 to 10 years after menopause. Then, for several years, the breakdown of bone occurs at a much greater pace than the building of new bone. This is the process that eventually causes osteoporosis.

During this time, even though your bones may still be strong enough to prevent unusual fractures and you have no signs to alert you to the disease, bone loss may become detectable with a bone density test.

Yes. Men get osteoporosis. In fact, about 2 million men over age 65 have osteoporosis. Osteoporosis usually starts later and progresses more slowly in men.  But by age 70, men catch up to women in the rate they lose bone.

Because men tend to be older when they get osteoporosis, the complications from broken bones can be more serious for them. Hip, spine, and wrist bones break most often.

With the aging of America, osteoporosis is becoming increasingly common. Among people ages 50 and older, 55% are at significant risk for osteoporosis. In the U.S., more than 10 million men and women have osteoporosis. And nearly another 43 million are thought to have low bone density. That places them at increased risk for osteoporosis.

The rate of bone loss varies from person to person. But around midlife, bones become thinner. Many things influence how fast or how slow you lose bone.

  • Your activity level
  • How much calcium you get
  • Your family history
  • Your history of taking certain medications, like corticosteroids (a type of steroid medication that curbs inflammation), or others that suppress the immune system
  • Your lifestyle habits, such as whether you smoke or how much alcohol you consume
  • Whether you have certain chronic diseases that affect the kidneys, lungs, stomach, and intestines or change hormone levels
  • The onset of menopause

Estrogen is important for maintaining bone density in women. When estrogen levels drop after menopause, bone loss speeds up. This can happen with natural menopause or an early surgical menopause if you have your ovaries removed.

During the first 5 to 10 years after menopause, women can lose about 2.5% of bone density each year. That means they can lose as much as 25% of their bone density during that time.

Accelerated bone loss after menopause is a major cause of osteoporosis in women. For women, having the strongest bones possible before you enter menopause is the best protection against debilitating fractures.

About half of all women over age 50 and about 1 in 4 men will break a bone due to osteoporosis. But there are many things you can do to prevent osteoporosis and avoid painful fractures. For instance, make sure you get plenty of calcium in your daily diet. You can get calcium from both foods and supplements. You can also check your osteoporosis risk factors and change those you can control. For example, stop smoking if you are a smoker. If you need them, your health care provider can make recommendations about using osteoporosis medications.

A very important thing you can do is be sure to get plenty of exercise. Weight-bearing exercises stimulate the cells that make new bone. By increasing weight-bearing exercises, you encourage your body to form more bone. This can delay or even reverse the destructive process of osteoporosis that results in painful or debilitating fractures. By adding strength training to your exercise routine, you improve your muscle strength and flexibility and reduce the likelihood of falling. Talk to your health care provider about suitable exercise options for you.