What is a bone density test?
Bone densitometry is a non-surgical and painless method of measuring bone density. Bone density scanning, also called dual-energy x-ray absorptiometry (DXA or DEXA test) or bone densitometry, is an enhanced form of low dose x-ray technology that is used to measure bone loss and mineral content of bone. The test is very safe and exposes a person to the same amount of radiation that a person is naturally exposed to in one week. Bone densitometry is today's established standard for diagnosing problems and assessing bone health.
Bone densitometry is most often used to diagnose osteoporosis, a condition that often affects women after menopause but may also be found in men. Osteoporosis involves a gradual loss of calcium, as well as structural changes, causing the bones to become thinner, more fragile and more likely to break. Because osteoporosis can be so difficult to detect, your doctor may recommend a bone density test. It is the most practical way to accurately measure the density of your bones and can be useful in helping your doctor diagnose the disease, especially early on. Repeated over time, it can also help your doctor track your rate of bone loss.
Bone density is important as low bone mass is the most accurate predictor of an increased risk for fractured or broken bones. Once bones become weakened, the following symptoms of bone loss may occur: back pain, changes in posture (e.g., bending forward), loss of height over time and shortness of breath not caused by heart or other conditions, indicating a potentially compressed spine.
How is a bone density test done?
A bone density test is a painless examination that does not involve injections or contrast materials. You will likely have to wear a gown and have your height and weight measured. The lumbar spine/hips, along with various other skeletal sites, are usually examined.
The bone densitometer is like a large examination table. It is padded and comfortable. You will lie flat on your back, on the table, in a comfortable position and breathe normally. You should remain as still as possible during the procedure. This painless test typically takes 15 minutes or less. Generally, you can resume your usual activities immediately.
A radiologist will interpret your test results and send those results to your physician, who will share the results with you.
Who Should Have a Bone Density Test?
There are often no symptoms during initial stages of bone loss. For example, people with osteoporosis often aren't aware they have it until they break a bone. This is why bone density screenings are so important, to find bone loss before bone damage occurs.
Men should be screened at age 70 or earlier if they have one or more risk factors.
Risk factors for bone loss or bone problems include:
- Family history of bone problems such as osteoporosis or parental hip fracture
- Personal history of bone fractures
- Increased age - osteoporosis affects nearly 20% (1 in 5) of women aged 50 and older and almost 5% (1 in 20) of men aged 50 and older, according to the CDC.
- Abnormal hormone levels
- Race (more common in individuals who are white or Asian)
- Women who experience menopause prior to age 50, either naturally or by surgical removal of the ovaries
- Men with a history of prostate cancer or androgen (testosterone) deficiencies
- Use of high-risk medications such as diuretics, blood thinners or medications for gastric reflux/GERD
- Progressive loss of height or small stature of less than 5’4”
- Low body weight (under 120 lbs.)