What are X-rays?

An X-ray is the use of energy called radiation to make pictures of the inside of your body. As the X-rays pass through your body, different tissues absorb different amounts of radiation and show up in different shades of black and white on film or a computer screen. For example, the calcium in bones and teeth absorbs X-rays the most and makes the bones or teeth look white. Lungs are full of air, which absorbs X-rays the least, so the lungs look black. Fat and other tissues show up in various shades of gray.

When are they used?

X-rays are used to help diagnose many diseases and problems. They can show problems like broken bones, dislocated joints, tumors, or cavities in your teeth. Muscles, brain and blood vessels cannot be seen well with plain X-rays. Dyes or computers may be used with X-rays to see these tissues.

How do I prepare for an X-ray exam?

You may need to remove jewelry, eyeglasses, and anything else with metal if it is near the part of your body being X-rayed. Because metal shows up on X-rays, it might get in the way of what your provider is trying to see.

Tell your provider if you have had any kidney problems or reactions to foods or chemicals, such as X-ray contrast dye. Contrast dye is used for some X-rays.

There are no other special preparations for most X-ray exams. If you are having an exam that requires preparation, your provider will give you instructions.

What happens during the exam?

X-rays may be done in a healthcare provider’s office, imaging center, or hospital.

Usually you undress to expose the area being examined. You may sit or lie down on a table. You will get into a position that gives a clear view of the part of your body being examined. Pillows or foam pads may be used to help you lie in the correct position. The X-ray technologist may cover parts of your body with lead aprons to protect those areas from radiation, such as the breasts or reproductive organs.

For some X-rays, contrast dye may be needed to help show the part of the body being filmed. Contrast dye may be given in different ways. It may be:

  • Injected into a vein
  • Given as a chalky liquid that you drink
  • Given into your rectum as an enema

The dye may make you feel warm. Your face may get flushed and you may get a headache or have a salty taste in your mouth. In rare cases, the dye can cause nausea and vomiting.

The X-ray technologist will put the X-ray machine in the proper position. The technologist will leave the room or go behind a protective screen or wall to take the X-ray image.

It takes only a second for a simple X-ray film to be taken (like taking a photo). You may need to hold your breath or stay still while the X-ray picture is being taken. Several films may be taken for different views.

Having an X-ray is usually painless. However, it might cause some pain if you have to be in an uncomfortable position while the X-ray is being taken.

After the X-ray films are taken, they must be developed. The development takes just a few minutes. The X-ray technologist will check the images to make sure no other pictures need to be taken before you leave.

After the technologist has checked the films, a healthcare provider or a radiologist will look at the pictures and interpret them. Radiologists are doctors who have special training in reading X-ray films and other types of images.

What are the risks of an X-ray exam?

Every procedure or treatment has risks. Some possible risks of an X-ray exam include:

  • In rare cases you may have an allergic reaction to dyes used during the exam.
  • If you are pregnant, there is a risk the X-rays will hurt the baby.
  • The radiation you get from an X-ray may cause a small increase in your lifetime risk of developing cancer. Modern equipment produces high-quality images using the lowest possible amount of radiation.

Ask your healthcare provider how these risks apply to you. Be sure to discuss any other questions or concerns that you may have.

Developed by RelayHealth.
Adult Advisor 2015.1 published by RelayHealth.
Last modified: 2015-02-03
Last reviewed: 2013-12-04
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
Copyright ©1986-2015 McKesson Corporation and/or one of its subsidiaries. All rights reserved.

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