An X-ray is a painless medical imaging test that can help in the diagnosis of many conditions. A machine takes an internal image of the part of the body being X-rayed.
X-ray machines use a kind of electromagnetic radiation that's similar to visible light but that has a little more energy. When these rays pass through the body, they provide an image of internal structures.
When people talk about X-rays, they often mean plain, conventional X-rays—formally referred to as radiographs. A broader range of medical imaging tests, such as computed tomography, use technologies which rely on X-rays.
X-ray machines pass X-ray beams through whichever part of the body a healthcare provider wants to see an image of, which may include soft tissue, organs, bones, or teeth. Providers use X-rays to help diagnose and sometimes monitor a variety of conditions.
One of the most common reasons you'd need an X-ray is to confirm whether you have a broken bone. Looking at the images of your bone, the healthcare provider can also determine if you need surgery or a cast.
An X-ray of a bone can also be helpful if you have chronic back or joint pain, as the image can reveal problems like injuries, infection, arthritis, or abnormal bone growths.
Someone coughing and having difficulty breathing might need an X-ray of the chest. A chest X-ray gives information to help diagnose issues like heart failure, pneumonia, or lung cancer.
If you have symptoms like abdominal pain or vomiting, your healthcare provider might recommend an abdominal X-ray to detect issues like a kidney stone or a blockage in your intestines.
Compared to some other imaging techniques, traditional X-rays are fast, easy-to-perform, and relatively inexpensive. Because of this, X-rays are often the first imaging test that you might receive for certain symptoms or suspected conditions, like pneumonia. They can be useful for people in the emergency room and helpful for less urgent situations too.
You might also get routine X-rays during dental visits. These X-rays can help diagnose and manage diseases and injuries of your teeth and gums.
Types of X-Rays
Many types of conventional X-rays and broader X-ray technologies—tests that use X-ray alongside other imaging techniques—exist. They include:
Conventional X-rays
When people talk about needing an X-ray, they usually mean conventional X-rays, otherwise known as radiographs. Examples of conventional X-rays include:
- Chest X-ray: This is one of the most commonly performed X-rays. It can help evaluate the lungs, heart, and chest wall.
- Abdominal X-ray: This shows a picture of inside the abdominal cavity, giving information about the stomach, liver, intestines, and spleen. Sometimes it is called a KUB X-ray if the kidney, ureter, or bladder is being studied.
- Bone or joint X-ray: X-rays are one of the easiest ways to diagnose a fracture or a dislocated joint. Depending on the situation, you might get an X-ray of body parts like your ankle, wrist, spine, leg, arm, or skull.
Conventional Radiographs Plus Contrast
Sometimes an X-ray is performed on its own. Other times X-rays include what's known as contrast material. Contract material is a substance you take into your body—whether orally, as an enema, or directly into your vein—before the X-ray. When the X-ray is taken, the material helps the X-ray images better display certain internal structures.
Some examples of X-rays that might be paired with contrast include:
- Angiogram: This procedure that uses X-rays can provide information about different blood vessels in the body, such as the presence of an abnormally bulging artery (aneurysm). You’d receive the contrast agent into your artery before an angiogram.
- Intravenous pyelogram or cystogram: For this X-ray of your urinary system, you'd receive a contrast agent into your veins. The imaging might reveal structural abnormalities with the kidneys.
- Abdominal x-ray with contrast: Depending on the part of the gastrointestinal tract being studied, you might take a contrast agent orally or via an enema.
Other X-Ray Technologies
A variety of other medical tests use X-rays.
For example, mammography is a type of X-ray technology specifically designed to get images of the breast, often for early detection of breast cancer. It uses low doses of X-rays.
Another example of an imaging procedure that uses X-ray is fluoroscopy. Instead of a single image like a conventional X-ray, fluoroscopy provides a continuous stream of X-rays and images which can show organs in motion. For example, in what is called an upper GI series, fluoroscopy can help identify abnormalities of the gastrointestinal tract.
Computed tomography (CT) uses X-ray radiation to provide detailed three-dimensional views of a part of the body, like the abdomen. It’s more expensive and less convenient compared to conventional X-rays.
An X-ray machine creates X-rays, a kind of electromagnetic radiation. The part of the body that is being X-rayed is put between the machine and an X-ray detector.
When the X-ray machine turns on, it releases X-rays, which painlessly travel through the part of the body being imaged. On the other side, the X-ray detector measures the X-rays that have passed through the body. The X-ray detector can make an X-ray image (the radiograph) based on the different amounts of X-rays that make their way onto the detector.
Certain tissues block X-rays more than others. Dense tissue, like bone, absorb more X-rays and so shows up on the image as whiter. X-rays can travel more easily through less dense tissue, so air in the lungs, fat, or tissue appears as darker shades of gray on the X-ray image.
Before the X-Ray
There is typically no special preparation that's needed for an X-ray. If you're undergoing an X-ray with contrast, you will have to take the contrast material prior to your imaging. A healthcare provider will either inject the material into your vein or instruct you to take it orally or through an enema.
For some X-rays, such as dental X-rays, they may have you put on a lead apron over parts of your body that aren't being imaged.
During the X-Ray
The technician will help you get in the right position for the X-ray, which will depend on the type of X-ray being performed. You might stand or lie at a certain angle.
The technician will let you know when the X-ray is about to happen. You’ll need to stay very still for a few seconds. Depending on the X-ray, you might need to breathe deeply and hold that breath while the image is taken. You won’t feel any pain from the X-ray itself.
For some types of X-rays, you’ll need more than one view. So after someone helps reposition you, they take an X-ray from a different angle.
After the X-Ray
You shouldn’t feel any side effects from your X-ray. If you receive an X-ray during an appointment at a place like a radiology center, you can go about your day-to-day activities normally and await for follow-up or further instruction from your healthcare provider. If you receive an X-ray as part of a care plan when you are staying at a hospital, your healthcare team will advise you of your next steps.
Risks and Precautions
Conventional X-rays are relatively safe procedures, which is part of why they are used so frequently.However, there are some risks that should be considered.
Radiation Risks
The main risk from X-ray imaging procedures is exposure to the X-rays themselves. Theoretically, the rays might damage the genetic material in your body as they pass through, which may increase cancer risk.
However, the amount of radiation you get from an X-ray is small. Humans are exposed to some radiation in our everyday lives. If you are getting a chest X-ray, the amount of radiation you receive is roughly equivalent to 10 days of radiation you'd get just from living your daily life.
So if you are getting a single X-ray, any increased risk of cancer is extremely low. The benefits of the medical information an X-ray can provide outweigh the potential risk radiation exposure brings.
Some kinds of X-ray technologies use greater amounts of radiation, though. For example, fluoroscopy uses more radiation than a single X-ray image. And a chest CT uses about 60 times the amount of radiation as a conventional chest X-ray. But healthcare providers try to minimize radiation risk for these and any other radiological procedure.
Pregnancy Risks
Certain kinds of X-rays may carry a small risk to the developing baby, like an increased risk of birth defects or miscarriage. Researchers think X-rays of areas like your arms are safe during pregnancy but that you should generally should avoid certain X-rays, like ones for the abdomen or pelvis.
Because the risk is probably low, in some circ*mstances it may still be the right choice to get an X-ray. Other times, an imaging choice that doesn’t use X-rays, like ultrasound or magnetic resonance imaging (MRI), may be a better approach.
If you are pregnant or think you may be, let them know before the X-ray process begins.
Contrast Agent Risks
Contrast materials you may need to take as part of your X-ray could pose some risks. While the specific risks vary based on the kind of contrast you receive, some possible mild reactions include nausea, headache, stomach cramps, and diarrhea. Let your healthcare provider know if such side effects don’t go away soon.
You should immediately get medical attention if you experience any signs of a potentially severe allergic reaction like bumpy, itchy skin; difficulty breathing; or swelling in your throat. Luckily, severe reactions to contract material are rare.
Depending on when and why you're getting an X-ray, you might receive it at an outpatient clinic or while you are in the hospital. If you have an appointment for an X-ray at an outpatient radiology center, bring an insurance card if you have one, photo ID, and any forms for the test. You may need to fill out some paperwork before the test.
Wear comfortable clothing. Depending on the X-ray, you might be able to keep some or all these on, or you might need to change into a hospital gown. Leave anything metallic, like jewelry, at home, as it can interfere with the X-ray.
Typically, you won’t need to fast before your X-ray. However, for certain kinds of abdominal X-rays, your healthcare provider might ask you to avoid eating for a certain number of hours ahead of time.
Usually, you won’t need to make any changes to your medications. If you’ve recently taken a medication like Pepto-Bismol (bismuth subsalicylate), let your provider know, as these can show up on the X-ray.
Results
The X-rays taken during the appointment may be digitally sent to a radiologist (a doctor trained in performing and interpreting radiation procedures) who can examine the X-ray images. They will then give a report to the healthcare provider who sent you to get the X-ray.
How long it takes to hear about your results—and how you are told—depends on the medical context. If it was a scheduled appointment at a radiology center, your prescribing provider might call you with results. If you're in a hospital setting, the results might come more immediately.
Interpreting Your Results
Interpreting X-ray results depends a lot on the specific X-ray you are getting and the reason you are getting it.
X-rays don’t come back “positive” or “negative” the way other test results might. Instead, the person reviewing the X-ray provides a description and their medical interpretation of what they see.
Sometimes results from an X-ray are straightforward and follow-up tests aren’t needed. For example, it might show a clear broken bone that needs to be treated.
Other times the results aren’t as clearcut. An X-ray may also occasionally show a finding that is difficult to interpret. An unexpectedly whitish area on an X-ray might represent a true clinical problem, like cancer, or it might be from a piece of jewelry that wasn’t removed. Sometimes follow-up exams or tests are needed for further clarification.
X-rays are images of the inside of your body produced using electromagnetic radiation. X-rays can help with the diagnosis and management of certain conditions, including fractures, pneumonia, and intestinal blockages.
X-rays are common, quick, and painless medical tests that require little preparation. While getting an X-ray does expose you to low levels of radiation, the medical benefit of getting the test is often considered to outweigh any potential risk. If you are getting an X-ray, speak to your healthcare provider if you have any concerns, are pregnant, or may be pregnant.
