Bone Density (DEXA) Scan
A bone density scan, often called a DEXA scan, uses a low dose of X-rays to measure how strong and dense your bones are. It helps doctors detect thinning bones and osteoporosis, and estimate your risk of fractures, so that steps can be taken to protect your bones.
Overview
What is a DEXA scan?
A DEXA scan, short for dual-energy X-ray absorptiometry, is a quick imaging test that measures the density and strength of your bones using a low dose of X-rays. It usually focuses on the hip and spine, where fractures are most serious. The measurement tells doctors how healthy your bones are compared with expected levels.
Why is a DEXA scan done?
A DEXA scan is mainly used to check for osteoporosis, a condition in which bones become weak and break more easily. It is often recommended for older adults, people who have broken a bone after a minor fall, and those with risk factors such as long-term steroid use. The result helps guide treatment to lower fracture risk.
Test Details
How do I prepare for a DEXA scan?
Very little preparation is needed. You can usually eat and drink normally, but you may be asked to stop taking calcium supplements for about a day beforehand. Wear loose, comfortable clothing without metal zips, buttons, or buckles, as metal can affect the images. Tell the team if you might be pregnant or have recently had a scan using contrast dye.
What happens during a DEXA scan?
You lie on your back on a padded table while a scanning arm passes slowly above you. The machine is open, so it does not enclose you, and you simply need to stay still and breathe normally. The scan is completely painless and usually takes only about 10 to 20 minutes to complete.
Results and Follow-Up
What happens after the test, and what do the results show?
Your results are often expressed as a T-score, which compares your bone density with that of a healthy young adult. A score in the normal range is reassuring, while a low score may indicate reduced bone density or osteoporosis and a higher fracture risk. Your doctor will explain your score and may suggest lifestyle changes, supplements, or medication.
Additional Common Questions
Is a DEXA scan safe?
Yes. The dose of radiation is very low, much less than a standard chest X-ray, so the scan is considered safe for most people. If you might be pregnant, tell the team beforehand.
How long does a DEXA scan take?
The scan itself is usually finished within about 10 to 20 minutes, and you can go home and return to your normal activities straight away.
Do I need to undress for a DEXA scan?
Often you can stay in your own clothes, as long as they have no metal parts. Sometimes you may be asked to change into a gown to keep metal out of the scan area.
This health topic is for general information and is not a substitute for professional medical advice. Always consult a qualified clinician about your individual situation. See our medical disclaimer.