A quick, painless test that produces images of the structures inside your body — particularly your bones. X-ray beams pass through your body, and they are absorbed in different amounts depending on the density of the material they pass through. Dense materials, such as bone and metal, show up as white on X-rays. The air in your lungs shows up as black. Fat and muscle appear as shades of gray.
For some types of X-ray tests, a contrast medium — such as iodine or barium — is introduced into your body to provide greater detail on the images.
Some people worry that X-rays aren't safe because radiation exposure can cause cell mutations that may lead to cancer. The amount of radiation you're exposed to during an X-ray depends on the tissue or organ being examined. Sensitivity to the radiation depends on your age, with children being more sensitive than adults.
Generally, however, radiation exposure from an X-ray is low, and the benefit from these tests far outweigh the risks.
However, if you're pregnant or suspect that you may be pregnant, tell your doctor before having an X-ray. Though the risk of most diagnostic X-rays to an unborn baby is small, your doctor may consider another imaging test, such as ultrasound.
In some people, the injection of a contrast medium can cause side effects such as:
Different types of X-rays require different preparations. Ask your doctor or nurse to provide you with specific instructions.
In general, you undress whatever part of your body needs examination. You may wear a gown during the exam, depending on which area is being X-rayed. You may also be asked to remove jewelry, eyeglasses and any metal objects because they can show up on an X-ray.
Before some types of X-rays, you're given a liquid called contrast medium. Contrast mediums, such as barium and iodine, help outline a specific area of your body on the X-ray image. You may swallow the contrast medium or receive it as an injection or an enema.
After an X-ray, you generally can resume normal activities. Routine X-rays usually have no side effects. However, if you're injected with contrast medium before your X-rays, drink plenty of fluids to help rid your body of it. Call your doctor if you have pain, swelling or redness at the injection site. Ask your doctor about other signs and symptoms to watch for.