Bones are made up of living tissues that are continuously being dissolved and replaced. But when bone loses minerals (like calcium) faster than they can be replaced, osteoporosis occurs.  

Osteoporotic bones lose density or mass, which causes them to weaken and become more likely to break. When bone becomes weak and brittle, small incidences – a minor fall or simply moving the wrong way – can turn into a broken bone.  

Luckily, there is a way to measure the strength of your bones to find and treat bone loss before it becomes a problem. 

What is a Bone Density Test, and How Is It Done? 

A bone density test is a special type of low radiation X-ray, referred to as a DEXA (dual-energy X-ray absorptiometry) scan, or DXA,  that measures bone mineral density to help a doctor determine if a patient has or is at risk for osteoporosis.  

A DXA is a simple, quick, and non-invasive procedure. There is generally no prep required and it takes only about 10 minutes – no more than a half-hour.  

DXA test results are reported in two categories: T-score and Z-score. 

T-Score 

A bone density T-score compares your bone mineral density against that of a healthy young adult. For example, older men would have their bone health tested against a healthy young male’s bone health. 

If the T-score ranges from -1 or above, there's nothing to worry about. If the T-score is between -1 and -2.5, you have osteopenia, another term for bone loss, which can lead to the beginning stages of osteoporosis.  A T-score of  -2.5 or lower indicates an established case of osteoporosis. 

Z-Score 

The Z-score compares your bone density to the average bone density of people your own age gender, and ethnicity. This scoring system is used for children, women before menopause, and men under the age of 50. If you measure lower or higher than the average, medical professionals may recommend further monitoring of your health and future bone density testing, as well as a check to see if there are other medical conditions or current medications that might cause further decline in bone density. 

Why Test for Bone Density? 

Measuring bone density allows a doctor to see if a patient has osteoporosis and may be at risk for dangerous fractures, breaks, and sprains. It can also be an important measurement that can help guide treatment later on, especially when other issues arise. 

"Testing for bone density is our way to get a better look at a patient's bone health,” says Summit Health Endocrinologist, Dr. Erica Weitzner. "If a patient has osteoporosis, we can immediately start exploring treatment options to help prevent fractures. We aim to get patients tested well before they have any broken bones." 

Who Should Get a Bone Density Test? 

There are several risk factors to consider when determining if you're eligible for a bone density X-ray. Certain pre-existing health conditions, medications, and heavy alcohol use can also increase risk for osteoporosis. 

Below are the official recommendations from the International Society of Bone Densitometry (ISCD): 

Indications for Bone Mineral Density (BMD) Testing include: 

• Women aged 65 and older 

• For post-menopausal women younger than age 65, a bone density test is indicated if they have a risk factor for low bone mass such as:  

• Low body weight 

• Prior fracture 

• High risk medication use 

• Women during the menopausal transition with clinical risk factors for fracture, such as low body weight, prior fracture, or high-risk medication use 

• Men aged 70 and older 

• Adults with a condition associated with low bone mass such as rheumatoid arthritis 

• Adults on medications associated with low bone mass or bone loss such as oral steroids 

When Should You Get a Bone Density Test? 

Depending on your unique health profile and risk factors, your doctor may recommend a bone density test after fracturing a bone, reaching a certain age, or experiencing a decrease in hormones. While most experts suggest women 65 years and older should undergo screening for osteoporosis, there are times when younger women or men should be tested as well. 

How Do You Prepare for a Bone Density Test? 

There is no preparation involved for a DXA test. If, however, you are a patient who takes calcium supplements, your medical professional may tell you to stop using them 24 hours prior to the test. 

Final Thoughts on Bone Density Tests and How They Work 

Let's face it; aging can be a pain. The spine, hips, and other bones can lose bone mass and create serious physical health problems. While it’s definitely beneficial to make a conscious effort to reduce your fall risk and be extra careful during certain activities, the extra information offered from a bone density test can help ensure you stay as healthy and safe as possible.  

Learn more about DXA scans here. Be sure to also check out Summit Health's endocrinology and orthopedics departments for more information on the services and treatments we provide for patients. 

At Summit Health we are dedicated to your overall well-being. If you are concerned about your balance or risk of falling, please bring up the topic with your provider so they discuss ways to help you.