Bone Density Testing

Osteoporosis is a disease in which bones become fragile and more likely to break, caused by gradual loss of bone. Osteoporosis is responsible for the loss of height, stooped posture (curvature of the spine) and broken hips or wrists seen in many older women. The diagnosis is nearly always made after someone breaks a hip, or develops a spinal bone fracture (called a vertebral compression fracture). By then, the patient may have lost more than 25% of their total body bone content, a process which occurred invisibly over many years.

Currently, 28 million Americans (of whom 80% are women) have either decreased bone density or actual osteoporosis and most don't even know it. The medical costs of dealing with osteoporosis are upwards of $14 billion dollars per year, attributable to 1.5 million osteoporosis-related bone fractures per year. Osteoporosis can be debilitating and even deadly. Two hundred thousand women break a hip every year. Twenty (20) % of these women will die within one year and 25% of the survivors will be confined to nursing homes.

DEXA Testing

Bone density testing is presently the ONLY method for determining whether or not an individual has osteoporosis. The testing is done using a special kind of x-ray technique, called DXA (which stands for Dual-energy X-ray Absorptiometry). There are two types of DXA bone density tests available, called central and peripheral. Central DXA is a scan of the hip and the lower spine. It is done in a hospital X-ray department or some doctor's offices on a large X-Ray device,  typically at a cost of over $300.

DEXA testing is available at the Pasadena Randall Breast Center. For our existing patients, we can arrange this test for you.

Know Your 'T' Score

There are 3 possible results from a DXA scan: normal, osteoporosis or in-between, called osteopenia. The DXA result is reported as a T-score. The T-score compares the measured bone-density to that of an average individual's peak bone density (which naturally occurs about age 30). A normal result is any T-score value greater than (above) a minus 1. A T-score of 0 (zero) means that your bone density is about the same as that of a 30-year-old! Good job if you get a zero.

Osteoporosis is present when the T-score is at minus 2 or below. This means that the individual has lost about 20% to 25% of their bone density compared to peak bone density. Osteopenia means diminished bone density. This is a T-score between minus 1 and minus 2. This indicates a loss of bone from 10-25% compared to peak bone density. With osteopenia, there is an increased risk for bone fractures, but there is also much hope for improvement with proper treatment.

Despite the ease, simplicity and usefulness of this peripheral DXA test, it is often not covered by insurance companies. Your insurance will be billed, but if they do not cover the test, the cost will be your responsibility. Early detection of diminished bone density is as valuable as a mammogram is for early detection of breast cancer. Whether or not your insurance covers the peripheral DXA test, be assured that having this test done is an important step in preventing osteoporosis, a serious and disabling condition.

Who should have a bone density test done?

A DXA test should be done if there is an increased risk of discovering low bone density. Sometimes it is done right at menopause or a few years after to establish a baseline, but some insurance companies may not consider this a valid medical indication.

Risk factors for low bone density include:

  • Caucasian and Asian Race
  • Post-menopausal not taking any hormones
  • Age over 65
  • Thin body build
  • Sedentary lifestyle
  • Long-term smoker
  • Poor calcium or dairy product intake for a long time
  • Family History of Osteoporosis
  • Loss of more than 2 inches in height after menopause
  • Diagnosed fracture such as spinal, wrist or hip for any non-obvious reason
  • Medical conditons such as taking steroids, hyperthyroidism, bone diseases, certain types of cancer
  • Breast cancer medications such as tamoxifen, arimidex, femara


All women over age 40 should be concerned with osteoporosis prevention. Before menopause, prevention consists of two major factors: calcium intake and exercise. After menopause, some type of estrogen-therapy in addition to calcium intake and exercise is usually necessary for reliable osteoporosis prevention. Vitamin D is also important. Many of us have low levels of Vitamin D due to little exposure to direct sunlight. It is reasonable for most people who work indoors to rake 1,000 to 2,000 units per day of Vitamin D.

Calcium intake should be about 1000 to 1200 milligrams daily. This is equivalent to 3-4 servings daily of a dairy product such as milk, yogurt, cheese or cottage cheese. Tofu and whole canned sardines are rich sources of calcium, as is calcium-fortified orange juice. Most women get inadequate calcium in their daily diet and therefore should probably take a 500-milligram calcium supplement daily to insure adequate calcium intake. 

Exercise should be weight bearing, meaning that the whole body is involved. Walking, jogging swimming, tennis or aerobics are excellent. The minimum recommendation is 30 minutes three times per week. More exercise than that is fine too !

If osteopenia or osteoporosis is diagnosed, additional measures may be necessary. Blood and urine tests can be done checking for calcium absorption and bone loss. Many medications to help build bone are available. Modern medicine has a lot to offer women who already have osteoporosis or are heading in that direction. Prevention is important for all women, but like many other serious disorders, it can be extremely useful to know exactly where you stand.

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