Chest x-ray for cancer of unknown primary

X-rays use high energy rays to take pictures of the inside of your body. They are a good way to look at changes in organs, such as the lungs.

You have x-rays in the imaging department of the hospital, taken by a radiographer.

Photograph showing a chest x-ray

Why you might have a chest x-ray

You might have an x-ray to help find the cause of your symptoms. For example, you might have a chest x-ray if you are having problems with your breathing. You may also have it to check that your lungs look healthy before treatment. For example, you might have it before an operation. Or to find out if the cancer has spread to your lungs. 

Some people have a CT scan of the chest instead of an x-ray.

What happens

There is no special preparation for a standard x-ray. You can eat and drink normally beforehand. You take your medicines as normal. If you are having another type of x-ray such as:

  • a barium x-ray
  • a CT scan
  • an angiogram

You might need to stop eating and drinking for a certain amount of time before the test. Your appointment letter will give you instructions you need to follow.

When you arrive, the radiographer might ask you to change into a hospital gown and take off any jewellery.

During your x-ray

You usually have a chest x-ray standing up against the x-ray machine. If you can’t stand you can have it sitting or lying on the x-ray couch. For x-rays of other areas of the body the best position is usually lying down on the x-ray couch.

The radiographer lines the machine up to make sure it's in the right place. You must keep very still to prevent blurring of the picture.

The radiographer then goes behind a screen. They can still see and hear you. They might ask you to hold your breath for a few seconds while they take the x-ray. 

X-rays are painless and quick. You won’t feel anything.

You might have more than one x-ray taken from different angles. The whole process may take a few minutes.

After your x-ray

After the x-ray you can get dressed and go home or back to work. 

Getting your results

Ask your doctor how long it will be until you get your x-ray results. Unless your doctor thinks it’s urgent the results might take a couple of weeks.

Waiting for test results can be a worrying time. You might have contact details for a specialist nurse and you can ask them for information. It may help to talk to a close friend or relative about how you feel.

For support and information, you can also contact the Cancer Research UK nurses on freephone 0808 800 4040. The lines are open from 9am to 5pm, Monday to Friday.

Possible risks

An x-ray is a safe test for most people but like all medical tests it has some possible risks. Your doctor and radiographer make sure the benefits of having the test outweigh these risks.


The amount of radiation you receive from an x-ray is small and doesn't make you feel unwell.

The risk of the radiation causing any problems in the future is very small. The benefits of finding out what is wrong outweigh any risk there may be from radiation.

Talk to your doctor if you are worried about the possible effects of x-rays.

  • Metastatic malignant disease of unknown primary origin in adults: diagnosis and management
    The National Institute for Health and Care Excellence (NICE), 2010

  • Cancers of unknown primary site: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow up

    K Fizazi and others

    Annals of Oncology, 2015. Vol 26, supplement 5

  • The Royal Marsden Hospital Manual of Clinical Nursing Procedures

    L Doherty and S Lister (Editors)

    Wiley-Blackwell, 2011

  • Essential Orthopaedics
    Miller and others
    Elsevier Health Sciences, 2010

Last reviewed: 
17 May 2020
Next review due: 
17 May 2024

Related links