Medically Reviewed by Nayana Ambardekar, MD on November 19, 2022
4 min read

X-rays are images that use a small doses of ionized radiation to take pictures of the inside of your body called radiographs.

X-rays can help doctors diagnose things like:

Doctors can also use X-rays to find an object that a child or adult swallowed. An X-ray can be used to check your lungs for signs of pneumonia or tuberculosis, to figure out why you have shortness of breath, or to see if you have heart failure.

Other ways doctors use specific X-ray procedures include:

  • Mammography: This is an exam that puts your breast between a support plate and a second plate called a paddle, then a series of X-rays are taken. Doctors look closely at the images for signs of cancer or other issues.

  • Computed tomography (CT) scan: A computer puts together a series of X-rays, taken from different angles, to make a 3D image and give your doctor a more detailed picture.

  • Fluoroscopy: Sometimes called an ”X-ray movie,” this procedure shoots a continuous X-ray through a part of your body so doctors can see that part and how it moves. It’s most commonly done to look at bones, muscles, joints, and organs like your heart, kidneys, and lungs.




Most X-rays don’t require any special preparation. The doctor may ask you to take off jewelry, eyeglasses, or any metal objects or clothing that could get in the way of the image.

Doctors can take images while you stand up or lie down. It depends on the area of your body being examined. The X-ray tube hangs over the table. The film is in a drawer under the table.

The machine sends a beam of radiation through your body. Your hard, dense bones block that beam, so they show up as white on the film below you. The radiation also goes through softer tissue like muscle and fat, which appear in shades of gray in the X-ray. The air in your lungs will look black in the image.

You won’t feel anything during an X-ray, but it can be hard to hold still, and the exam table might be uncomfortable. The technician may take images from a few different angles. They might use pillows or sandbags to prop up a body part to get a better view of the area. They’ll probably ask you to hold your breath so the image doesn’t blur.

Sometimes, the doctor needs more contrast on the image to clearly see what’s going on. They might give you a contrast agent, like barium or iodine. You’ll either swallow it or get it as a shot.

The machine makes clicks and buzzing sounds during the X-ray. The process could take just a few minutes for a bone X-ray or more than an hour for more complicated issues.


A radiologist will look at your X-rays. A radiologist is a medical doctor who is specially trained in reading and understanding the results of imaging scans like X-rays. X-ray images are digital, so a radiologist can see them on a screen within minutes in an emergency. For nonemergencies, it may take a day or so for them to review the X-ray and get back to you with the results.

X-rays are one of the oldest and most common forms of medical imaging. Doctors say the benefit of making the correct diagnosis outweighs the risks. Still, there are a few safety issues to consider.

  1. Slight cancer risk. Too much radiation exposure can cause cancer, but the amount in an X-ray is generally low. Adults are less sensitive to radiation than children.

  2. Kids and X-rays.If your child needs an X-ray, the technician may restrain them to make sure they stay still. This will prevent the need for repeated tries. It won’t hurt them. If you stay in the room with them, you’ll get a lead apron to wear to prevent radiation exposure.

  3. Pregnancy. Tell your doctor if you’re pregnant or think you might be. They may use a different imaging test so your baby isn’t exposed to radiation.

  4. Reaction to contrast agent. There’s a chance you could have an allergic reaction, but it’s rare. Ask your doctor what symptoms to watch for. Let them know if you have pain, swelling, or redness at the site of the shot.


X-rays are great to check for broken bones or rotting teeth, but other imaging tests are better if you have something happening with the soft tissue parts of your body such as the kidneys, intestines, or your brain. 

Your doctor may order an MRI instead of an X-ray to diagnose injuries like a ligament tear in your knee or torn rotator cuff in your shoulder. MRIs can also show tiny fractures or bone bruises, which may not appear on an X-ray, and it is often used to diagnose a broken hip. And MRIs are a good tool to see spine injuries, as doctors can see both the bones in your spine and spinal cord.

Doctors also may order a CT scan. A CT scan also may be used in an emergency room to diagnose problems such as a head injury, kidney stones or the cause of abdominal pain, or for diagnosing a blood clot in the lungs, which is also called a pulmonary embolism.