Bone mineral density test

What is a Bone Mineral Density Test?

A Bone Mineral Density (BMD) Test is a diagnostic procedure used to measure the amount of mineral contained within a person's bones. The test uses specialized X-ray equipment to take pictures of bones and measure how dense they are. Low bone density is an indicator of certain diseases, including osteoporosis, which increases your chance of fracture and other age-related bone problems.


Generally, you don't need to do anything special to get ready for a BMD test. You will be asked to remove any clothing containing metal or jewelry that might interfere with the X-ray. Also, if you have recently had any type of contrast dye injected for an exam, you may need to wait a few days before undergoing a BMD test.


A BMD test usually takes only a few minutes. During the procedure, you will lie on a table while a small device containing an X-ray detector is passed across your body, usually from your hips to your shoulders. The device records information about your bones that is used to calculate your bone density.

Types of BMD Tests

The most common type of BMD test is called Dual-Energy X-ray Absorptiometry, also known as DXA. During this test, the patient will be exposed to two different X-ray beams to measure bone density and mineral content. Another type of BMD test uses a procedure called Quantitative Ultrasound Transmission, which uses sound waves to measure the density of bone tissue.


The amount of radiation used in a BMD test is very small and usually considered safe. The risk of harm from the X-ray is lower than the potential risk of harm from an undiagnosed bone disease. It is a good idea to discuss any concerns you have with your doctor before undergoing a BMD test.

Why Have a BMD Test?

Having a BMD test is important in order to detect or monitor bone diseases, such as osteoporosis. Osteoporosis can weaken bones and make them more likely to fracture, leading to increased pain, disability, and even death. A BMD test can help determine if and how quickly a person's bones are weakening, allowing for early treatment that can help reduce the risk of fracture.

When Should a BMD Test be Performed?

The U.S. Preventive Services Task Force recommends BMD tests for all women 65 and older and all men 70 and older who are at risk for osteoporosis. Additionally, women under 65 who have a high risk for osteoporosis should also consider a BMD test. High risk factors include: being a smoker, drinking excessive amounts of alcohol, being underweight, having a family history of osteoporosis, or taking certain medications that can increase bone loss.