About X-rays

An X-ray is a quick and painless procedure that can help to diagnose and monitor a number of different health conditions. X-ray procedures are carried out by radiographers (health professionals trained to perform imaging techniques).

X-rays are commonly used to look for fractures in your bones after a fall or injury. They can also be used to look at your organs. For example, an X-ray image of your chest can show whether you have an infection in your lungs.

X-rays are a form of radiation. Unlike light radiation (normal light), which is absorbed or reflected by your skin, X-ray radiation passes through your body. An X-ray machine works by projecting a beam of X-rays through the part of your body that your doctor needs to look at. An X-ray sensitive detector then captures the radiation that comes out on the other side of your body in the form of a black and white image. This is called a radiograph.

Structures inside your body that are dense, such as your bones, absorb X-rays and show up white on the radiograph. Less dense structures, like the air in your lungs, let X-rays pass through them almost completely and show up black on the radiograph. Because different parts of your body vary in how dense they are, and absorb X-rays by different amounts, they show up on the radiograph as shades of grey, from the most dense (black) to the least dense (white).

The images captured by an X-ray machine are usually stored digitally and displayed on a computer screen. Sometimes X-rays are processed on film instead, and can be viewed by shining light over the film from behind.

What are the alternatives?

Depending on which part of your body is being looked at, a different type of imaging procedure may be more appropriate. Alternative tests may include an ultrasound scan, MRI scan or CT scan. Your doctor will discuss with you which test is most suitable.

Preparing for an X-ray

X-rays are usually done as an out-patient procedure in the radiology or imaging department of a hospital.

Your radiographer will discuss with you what will happen before, during and after the procedure. This is your opportunity to understand what will happen, and you can help yourself by preparing questions to ask about the risks, benefits and any alternatives to the procedure.

What to expect at the hospital

The examination is routinely done as an out-patient procedure in the radiology or imaging department.

Your radiographer will explain the procedure and ensure that you're happy to go ahead with the X-ray test. Radiographers are specially trained in imaging techniques and do most of the work in taking X-ray images. The images will then be sent to a radiologist (a doctor who specialises in using imaging methods to diagnose medical conditions).

What happens during an X-ray

X-rays usually only take a few minutes.

Depending on the area of your body that needs to be exposed to the X-rays, you may be asked to remove your clothing, put on a hospital gown and take off your jewellery. There will be a private area where you can do this.

You will then go to the X-ray room and your radiographer will help you to get into the right position on the X-ray machine. Alternatively, you may be asked to lie down on an X-ray table or sit in a chair at the side of the table, depending on the part of your body being looked at. You will be asked to stay still and sometimes, particularly if you’re having a chest X-ray, to take a deep breath and hold it for a few seconds.


Your radiographer will operate the X-ray machine from behind a screen, but will be able to see and hear you at all times. He or she may need to take more than one X-ray, and so you may have to get into a number of slightly different positions on the machine.

What to expect afterwards

You will usually be able to go home when you feel ready.

Usually, a report will be sent out by the radiologist to your doctor; your X-ray images may also be sent. This can take several days. Before you go home, ask your radiographer when you can expect to get your results. It may be possible to ask for a copy of your images on a disc. This is particularly useful if you will be seeing a doctor in a different hospital or, for instance, if you will be travelling abroad.

What are the risks?

As with every procedure there are some risks associated with having an X-ray. However, the benefits of having the procedure usually outweigh these risks. You will be exposed to some X-ray radiation, but the amount you receive isn't considered to be harmful.

Different X-rays expose you to different doses of radiation. For example, if you have a chest X-ray you will be exposed to a very small amount of radiation (about the same that you would naturally be exposed to over two to three days). Other tests such as a barium enema and barium swallow and meal involve having many X-ray images and therefore the radiation dose is higher. However, doctors are trained to keep your exposure to a minimum. Ask your radiographer to explain how these risks apply to you.

If you’re pregnant

Although the radiation from an X-ray is generally thought to be safe for adults, it may harm an unborn baby. Therefore, X-rays won’t usually be used on pregnant women unless there is an urgent medical reason. But if you’re pregnant and your doctor decides you need to have an X-ray, a lead shield will be used to cover your abdomen (tummy) to help protect your baby.

If you think you could be pregnant, tell your doctor before the day of your appointment. Your doctor will advise you whether or not to go ahead with the procedure.

My child needs an X-ray - can I go with him or her?


Yes, if your child is young, it's likely that you will be able to go with him or her into the X-ray room.


If you have a young child who needs to have an X-ray, you will usually be allowed to go into the X-ray room with him or her. You may be asked to wear a lead apron. This is to protect your body from radiation and will allow you to stay close to your child when the X-ray is being done.

If you’re pregnant, or if there is any chance that you could be pregnant, it may not be possible for you to go with your child into the X-ray room. This is because X-rays may be harmful to your unborn baby. 

If I have lots of X-rays, will my risk of getting cancer increase?


Having an X-ray can slightly increase the chance of you getting cancer many years later. However, the benefits of having this procedure should outweigh the very small risk.


You have about a one in three chance of getting cancer, even if you have never had an X-ray. The radiation from X-rays may add to your underlying risk of cancer by only a very small amount. For many routine X-ray tests, including those of your chest or your arm or leg, this increase in risk is extremely small. Having X-rays of your abdomen (tummy), hip or back exposes you to more radiation, but the increase in risk is still very small.

You're exposed to natural background radiation all the time. Cosmic radiation reaches us from outer space, radioactive material is in the ground and there is even radioactive gas (radon) in the air. The amount of radiation you're exposed to during a chest X-ray is the equivalent of a few days of this background radiation.

The number of X-rays you need to have will depend on your medical condition. Your doctor will make sure that any X-rays you have will be used to support your treatment. This means that the benefit of each X-ray you have will outweigh the very small increase in cancer risk that it causes.

You should let your doctor know if you have had any X-rays or scans recently, as this may mean that an additional test isn't needed.

I'm not sure whether I'm pregnant. Is it safe for me to have an X-ray?


If you’re pregnant, there is a small risk to your unborn baby if he or she is exposed to X-ray radiation. This is why X-rays aren't usually done on pregnant women. You must tell you doctor if you think you might be pregnant before you have the X-ray.


Unborn babies may be more sensitive to X-ray radiation than adults. Therefore, if you’re pregnant, you will usually be advised not to have an X-ray.

It's worth bearing in mind that the X-ray beams are focused on the area of your body being examined. This means that if you’re pregnant and need an X-ray image of your head or chest, you may be able to go ahead with the procedure as there is very little exposure to your abdomen (tummy) and pelvis. But if your doctor advises you to have an X-ray of your abdomen or pelvis, a lead shield that blocks X-rays can be used. This will help to protect your unborn baby from the radiation.

If you think you may be pregnant, even if it hasn't been confirmed yet, make sure that you tell your doctor. Your doctor will take this into account when deciding whether an X-ray is suitable for you.