A chest x-ray produces an image of the inside of the chest showing the bones, heart and blood vessels. Chest x-rays usually show the chest in two views: from the front and from the side. 

Although chest x-rays are not as sophisticated as some other diagnostic technologies, they provide information that cannot be obtained in an examination.

For instance, they can be valuable in initially evaluating:

• The size of the heart.
• The contour of the heart. Enlargement of a particular chamber or blood vessel may suggest heart failure or other abnormal functioning.  
• The size of the large blood vessels of the lungs. Enlarged blood vessels may suggest any of several heart defects or diseases - and indicate the need for more sophisticated tests.

How Does It Work?

During a chest x-ray, a beam with a small amount of radiation is directed through the chest. The radiation that passes through the body is recorded on film or by a computer. Tissue such as the lungs doesn’t absorb much radiation, and those areas appear darker on the x-ray image. Bones, which absorb a lot of radiation, appear white in the image.

How Is It Performed?

A chest x-ray is performed in your physician’s office or the hospital. The test itself is conducted by a radiology technician. For the x-ray, you will wear a hospital gown and be asked to remove all jewelry and objects containing metal. The technician will cover areas that could be exposed to radiation but that are not part of the area to be imaged with a lead apron or shielding. You will be asked to stand in front of the x-ray machine. While the x-ray is being taken, you will be asked to hold your breath for a few seconds to keep the image from blurring.

Is It Safe?

Medical tests, including chest x-rays, should not be ordered unless they can provide information that is not available through simpler, safer methods. While the exposure to radiation (including x-rays) is worthy of concern, the amount of radiation exposure in a chest x-ray is minimal. A few x-rays a year is not believed to cause harm. However, if you are pregnant, notify your doctor. X-rays are not typically performed on pregnant patients because of the risk to the baby. For more information about cardiovascular disease testing and radiation, see SecondsCount Guide to Radiation Safety in Medical Testing.

Questions to Ask Your Doctor About Chest X-ray

 The following questions can help you talk to your physician about having a chest x-ray. Consider printing out or writing down these questions and taking them with you to your appointment. Taking notes can help you remember your physician’s response when you get home.

• What are the possible benefits for me of having a chest x-ray?
• What are my individual risks from having a chest x-ray?
• How much radiation will I be exposed to during the test?
• What happens next if the chest x-ray shows something that needs further examination?

Please print this list of questions here. Take them with you to the doctor and share them with friends and loved ones when you are encouraging them to see their doctors.