About Bone Density

Bone density is a term that relates to the health and strength of your bones. When your bones are not strong they are susceptible to breaks. While many times broken bones can heal, a serious fracture can cause you to lose your independence. In severe cases it can be fatal. Low bone density is sign that you have osteopenia or osteoporosis. However, there are ways to improve your bone density and reduce your chances of a fracture.

Considerations

• Your bones are always changing. They are constantly being broken down and rebuilt. Cells called osteoclasts are constantly breaking down old bone and sending these old cells to be reabsorbed. Other cells called osteoblasts make new bone. The density of your bones is maintained when these two cells are working at the same rate. With age, we tend to naturally lose some bone mass. Maximum bone density is achieved between the ages of 15 and 25. Then, during menopause, women lose more bone than they build. Women can lose 20 percent or more bone mass after reaching midlife. Men lose bone mass too, but in general it is at a slower rate.

Bone Density Tests

• The only way to determine your bone density level involves having a specialized test called a bone density test. Another name for this test is a densitometry, or DEXA scan. This test, which is simple and painless, is similar to an X-ray. (See the picture at the top of this article.) A DEXA scan takes a picture of your bones to determine how much calcium and other minerals are present in the bone. These results are then compared to other people of the same gender, age and other characteristics.

Bone Density Measurements

• A DEXA scan results in a written report that gives an overview of your bone density health. This is relayed in T scores and Z scores. Your T score is your bone density compared with what is normally found in healthy young adults of your sex. Your T score is the number of units or standard deviations (SD) that your bone density is above or below the standard. If your T score is above -1, your bone density is considered normal. Between -1 and -2.5 or more is indicative of low bone density. A low bone-density score means you have osteoporosis. Your Z score is the number of standard deviations above or below what's normally expected for someone of your same gender, age, weight and racial origin. Low readings here can help your physician determine if a factor other than age is responsible for your low bone density. However, it is not used to diagnose osteoporosis in postmenopausal women.

Osteoporosis

• Osteopenia or osteoporsis are conditions that develop when your bone density becomes too low. The picture here from the National Institutes of Health shows a normal bone compared to a bone with low bone density. As the density of your bones decreases, they become more porous and lose strength. When this happens, you are more susceptible to breaking a bone. If you have a more mild case of osteopoenia, a fracture can occur as the result of a fall. In severe cases of osteoporosis, a fracture can occur just by lifting an object or sneezing.

Prevention/Solution

• Even though it is natural to lose bone mass with age, simple lifestyle habits can keep your bone mass from getting too low. Eat a well-rounded diet with adequate amounts of calcium and vitamin D. Stay away from products with caffeine, phosphorus and high salt content. These items can interfere with your body's ability to absorb and process calcium. Smoking and heavy alcohol use can also speed up bone loss. Getting regular exercise, especially weight-bearing exercise, is important as well. Weight-bearing exercise actually stimulates bone formation.
  If your bone density levels are very low, you may need to take medication. There are medications currently on the market that have been proven to rebuild bone and reverse osteoporosis.