Bone mineral density refers to the amount of minerals, namely calcium, in your bones. The bone density test is important for people who are at risk for osteoporosis.

The bone density test is also referred to as dual energy X-ray absorptiometry (DXA or DEXA). It’s an important test for osteoporosis.

Osteoporosis causes your bone tissue to become thin and frail over time, and can lead to fractures.

Read on to learn more about bone density, what the test involves, and more.

Bone density, or bone mass, refers to how much calcium and other minerals are in your bones.

Having more calcium in your bones means that they have a greater density, and are stronger. Stronger bones are less likely to fracture, or break.

Your doctor may order a bone mineral density test if:

  • they suspect that your bones are becoming weaker
  • you have symptoms of osteoporosis
  • you’ve reached the age when preventive screening is advisable

The U.S. Preventive Services Task Force recommends preventive screening for people assigned female at birth over the age of 65 years, as well as females under 65 years with at least 1 risk factor for osteoporosis.

Some risk factors for osteoporosis include:

The test requires little preparation. For most bone scans, you don’t even need to change out of your clothes.

However, you should avoid wearing clothing with buckles or zippers because metal can interfere with X-ray images.

The test may take place in your doctor’s office, if they have the right equipment. Otherwise, you may need to visit a specialized testing facility. Some pharmacies and health clinics also have portable scanning machines.

To perform a bone density test, the doctor will ask you to lie down on a bench or table.

There are two types of bone density scans: central DXA and peripheral DXA.

Central DXA

Central DXA involves lying on a table while an X-ray machine scans your hip, spine, and other bones of your torso.

Peripheral DXA

Peripheral DXA examines the bones of your forearm, wrist, fingers, or heel.

This scan is usually a useful screening tool to learn if you need a central DXA.

After a bone density test, your doctor will review your test results. The results, referred to as a T-score, are based on the bone mineral density of a healthy young adult compared with your own value.

T-scores can suggest the following:

  • A T-score of -1 or higher indicates healthy bone.
  • A T-score of -1 to -2.4 indicates low bone mineral density (osteopenia)
  • A T-score of -2.5 or lower indicates osteoporosis.

Your doctor will discuss your results with you. Depending on your results and the reason for the test, your doctor may want to do follow-up testing. They will work with you to come up with a treatment plan to manage any issues.

Because a bone mineral density test uses X-rays, there’s a small risk associated with radiation exposure.

However, the radiation levels of the test are very low.

Tell your doctor if you’re pregnant or believe you could be pregnant. X-ray radiation could harm the fetus.

Steps to increase bone density and overall bone health include:

  • getting enough regular exercise or physical activity, particularly weight bearing exercises
  • consuming enough calcium and vitamin D
  • spending time outdoors to get vitamin D from sunline
  • avoiding smoking
  • avoiding alcohol

Talk with your doctor for more advice on ways to increase bone density and reduce your risk of osteoporosis.

A bone density test is painless.

Bone density tests are generally accurate. They are more accurate than regular X-rays for assessing bone density.

Your doctor may recommend not taking calcium supplements at least 24 hours before a bone density test. You may not need to do anything else to prepare for a bone density test, but it’s best to avoid wearing clothes with metal buckles or zippers as they affect the X-ray.

Bone mineral density is how much calcium and other minerals are in your bones. The more dense your bones are, the less likely they are to break or fracture.

The bone mineral density test, or dual energy X-ray absorptiometry (DXA), is a scan to measure bone density. You may require the test if you are a female over the age of 65 years or are at risk of osteoporosis.

Your doctor can provide information about whether they recommend the bone density test. They can also suggest ways to improve bone mineral density, such as getting enough regular physical activity and consuming enough vitamin D and calcium.