Screening
Mammogram
A mammogram is a low-dose X-ray of the breast used to check for breast cancer, often before any symptoms appear. It is the main test in breast screening.
Quick answer
Mammogram: what it is and what the results mean
A mammogram is a specialised X-ray of the breast tissue. It can detect changes, including very small cancers, that are too small to feel, and is the basis of national breast-screening programmes.
- Why it is done: It is used to screen for breast cancer in people invited by age, and to investigate breast symptoms such as a lump, thickening or nipple change (a diagnostic mammogram).
- Understanding results: Images are examined by specialists.
What it is
A mammogram is a specialised X-ray of the breast tissue. It can detect changes, including very small cancers, that are too small to feel, and is the basis of national breast-screening programmes.
Why it is done
It is used to screen for breast cancer in people invited by age, and to investigate breast symptoms such as a lump, thickening or nipple change (a diagnostic mammogram).
What to expect
Each breast is briefly pressed between two plates while an X-ray is taken; this can feel uncomfortable for a few seconds but is quick. The whole appointment usually takes only a few minutes.
Understanding the results
Images are examined by specialists. Most results are normal; if an area looks unclear or abnormal, further tests such as an ultrasound or biopsy are arranged. Screening aims to find cancers early when treatment works best.
Good to know
Risks and limitations
The radiation dose is very low. Mammograms are highly useful but not perfect — they can miss some cancers and sometimes flag changes that turn out to be harmless, which is why further tests are used to clarify.
Education and reference only. This explains the test in general terms and is not medical advice. Always follow the specific instructions from the team arranging your test, and discuss your results with your clinician.
Answers
Mammogram: frequently asked questions
Does a mammogram hurt?
The breast is pressed firmly for a few seconds, which some people find uncomfortable or briefly painful, but it does not last long. Tell the staff if you are in significant discomfort.
How often should I have a mammogram?
In national screening programmes, mammograms are usually offered every few years within a certain age range. Your invitation will explain the schedule, and higher-risk people may be offered them more often.
Related tests
Other screening investigations
Sources
Where this is drawn from
- NHS — Tests and treatments
- NICE — diagnostic guidance
- Royal College of Radiologists / relevant professional body
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