What happens during breast screening?

Breast screening is carried out at special clinics or mobile breast screening units.It's carried out by female members of staff who take mammograms (X-rays of the breast).

The aim of screening is to detect breast cancer at an early stage, when any changes in the breast would be too small to feel and when there's a good chance of successful treatment and full recovery.

What happens on the day

When you arrive at the breast screening unit, the staff will check your details and ask you about any breast problems you have had. If you have any questions, please ask.

Mammograms are carried out by women called mammographers. You'll need to undress to the waist, so it may be easier to wear a skirt or trousers instead of a dress.

The mammographer will first explain what will happen. She will then place your breast onto the mammogram machine and lower a plastic plate onto it to gently but firmly flatten it. This helps to keep your breast still and helps ensure a clear X-ray.

The mammographer will usually take two X-rays of each breast one from above and one from the side. She will go behind a screen while the X-rays are taken. You have to keep still for several seconds each time.

Most women find the procedure uncomfortable and it can occasionally be painful. However, the compression is necessary to ensure that the mammogram is clear. Any discomfort will be over quickly.

The whole appointment takes less than half an hour and the mammogram only takes a few minutes.


After your breasts have been X-rayed, the mammogram will be checked for any abnormalities. The results of the mammogram will be sent to you and your GP within two weeks of your appointment. Read about understanding your results.

Not all breast cancers are found during screening. Breast cancer can develop between screening appointments. Even if you attend your screening appointments, it's still important for you to be familiar with your breasts, so you can spot any unusual changes early and report them to your GP. Read about the symptoms of breast cancer.

Whento phone the breast screening unit beforehand

Please phone your breast screening unit (contact details will be on your invitation letter) before coming for your appointment if:

  • You have a physical disability or find climbing steps difficult, so your screening unit can make any necessary arrangements for you.
  • You have breast implants mammography can be less effective in women who have breast implants because the X-rays cannot 'see' through the implant to the breast tissue behind it. You will usually be able to have a mammogram, but please let the screening staff know beforehand. Read an NHS leaflet about breast implants and breast screening.
  • You have had a mammogram recently, or are pregnant or breastfeeding, as you may be advised to delay breast screening.
Content supplied by the NHS Website

Medically Reviewed by a doctor on 30 Nov 2016