An X-ray is 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.
Bones and teeth
- Fractures and infections. In most cases, fractures and infections in bones and teeth show up clearly on X-rays.
- Arthritis. X-rays of your joints can reveal signs of arthritis. X-rays taken over the years can help your doctor determine if your arthritis is worsening.
- Dental decay. Dentists use X-rays to take pictures of the teeth and jaw and check for cavities.
- Osteoporosis. Special types of X-ray tests can measure bone density.
- Bone cancer. X-rays can reveal bone tumors.
- Lung infections or conditions. Evidence of pneumonia, tuberculosis or lung cancer can show up on chest X-rays.
- Breast cancer. Mammography is a special type of X-ray test used to examine breast tissue.
- Enlarged heart. This sign of heart failure shows up clearly on X-rays.
- Blocked blood vessels. Changes in blood flow to the lungs and heart can be seen on chest X-rays.
- Digestive tract problems. Barium, a contrast medium delivered in a drink or an enema, can help reveal problems in your digestive system.
- Swallowed items. If your child has swallowed something like a key or a coin, an X-ray can show the location of that object.
What you can expect
During the X-ray
They are performed at doctors’ offices, dentists’ offices, emergency rooms and hospitals — wherever an X-ray machine is available. The machine produces a safe level of radiation that passes through your body and records an image on a specialized plate. You can’t feel an X-ray.
A technologist positions your body to obtain the necessary views. Pillows or sandbags may be used to help you hold the position. During the test, you must stay still (and sometimes hold your breath to avoid moving) to prevent blurry images.
An X-ray procedure may take from a few minutes for a bone X-ray to more than an hour for more-involved procedures, such as those using a contrast medium.
Your child’s X-ray
Restraints or other techniques may be used to keep a young child still during an X-ray. These won’t harm your child. They will prevent the need for a repeat procedure, which may be necessary if your child moves during the X-ray exposure.
You may be allowed to stay with your child during the test. If you do, you’ll likely be asked to wear a lead apron to shield you from unnecessary exposure.
After the X-ray
After an X-ray, you generally can resume normal activities. Routine X-rays usually have no side effects. However, if you receive contrast medium before the test, 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.