Osteoporosis, which means porous bones, is a progressive condition in which bones become structurally weak and are more likely to fracture or break. It is sometimes called a “silent” disease, because bone loss often occurs without your knowing it.

Normally, the body forms enough new bone tissue to balance the amount of bone tissue broken down and absorbed by the body. This is a natural process called bone turnover. Throughout the early part of your life, the amount of bone lost and the amount gained remains balanced. Bone mass (size and thickness) increases during childhood and early adult life, reaching its maximum by the age of 20 to 25.

Menopause, which usually occurs in a woman’s 40s or 50s, dramatically speeds bone loss. Older men lose bone mass as they age, as well. Osteoporosis develops when your body loses bone faster than it can form new bone. Over time, the imbalance between bone breakdown and formation causes bone mass to decrease, so fractures occur more easily.

Bones in the hip, spine, and wrist are especially prone to fragility fractures—fractures that would not have occurred in a younger person with stronger bones.

Forty percent of women and 25 percent of men over age 50 will have an osteoporosis-related fracture in his or her remaining lifetime. More than 2 million fractures occur in the United States each year and these fractures can lead to serious health problems.

Osteopenia, or low bone mass, is a more moderate decline in bone density than occurs in osteoporosis. If you have been diagnosed with osteopenia, or even osteoporosis, you can take steps to prevent further bone loss.

You need to exercise and get enough calcium and vitamin D to help keep your bones strong. You also may need to take medications for osteoporosis treatment. Ask your physician what action is right for you. Physicians agree that postmenopausal women and older men with osteoporosis should be medically treated to prevent fractures. (See Osteoporosis Treatment Options)

What role do hormones play in bone disease?

Too much or too little of certain hormones in the body can contribute to osteopenia and osteoporosis.

During and after menopause, the ovaries make much less of the hormone estrogen. Estrogen loss may also occur with surgical removal of the ovaries or because of excessive dieting and exercise. Estrogen helps protect bone.

Men produce less testosterone and estrogen—produced in small amounts in males) as they age. Reductions in these hormones may also contribute to bone loss.

Bone loss can result from the damaging effects of excess cortisol, as occurs in Cushing’s syndrome. Sometimes the adrenal glands produce excess cortisol because of a pituitary gland or other tumor. More commonly, Cushing’s syndrome develops as a result of long-term use of corticosteroid medications (steroids) such as prednisone and cortisone, used to treat inflammatory disorders like rheumatoid arthritis or asthma.

Other hormone imbalances that may increase the risk of osteoporosis include an overactive thyroid gland, diabetes, and hyperprolactinemia, in which the pituitary gland produces too much of the hormone prolactin.

Thyroid cancer survivors whose treatment includes high doses of thyroid hormone also have a higher risk.

Eating disorders, especially anorexia nervosa, increase the risk of osteoporosis. Bone loss occurs partly because of poor nutrition and, in women, partly because the ovaries stop functioning normally, producing less estrogen.

Who is at risk for osteoporosis?

According to the National Osteoporosis Foundation (NOF), osteoporosis is a major public health threat for more than 44 million Americans—or 55 percent of those 50 years of age and older. About 10 million individuals in the United States already have the disease and almost 34 million more have low bone mass, placing them at risk for osteoporosis. Eighty percent of those affected by osteoporosis are women.

Excessive bone loss occurs more often in certain groups of people. Your risk of developing osteoporosis is higher if you:

1. are older

2. have a family history of osteoporosis

3. have a thin or small frame

4. have completed menopause

5. are Caucasian or Asian

6. have had a fracture as an adult

7. have a parent with hip fracture

© 2012 The Hormone Foundation. All rights reserved.