About 1 in 8 women in the UK are diagnosed with breast cancer during their lifetime. If it's detected early, treatment is more successful and there's a good chance of recovery.
Breast screening aims to find breast cancers early. It uses an X-ray test called a mammogram that can spot cancers when they're too small to see or feel.
But there are some risks of breast cancer screening that you should be aware of.
As the likelihood of getting breast cancer increases with age, all women aged from 50 to their 71st birthday, and registered with a GP are automatically invited for breast cancer screening every 3 years.
In the meantime, if you're worried about breast cancer symptoms, such as a lump or area of thickened tissue in a breast, or you notice that your breasts look or feel different from what's normal for you, don't wait to be offered screening – see your GP.
Why is breast screening offered?
Most experts agree that regular breast screening is beneficial in identifying breast cancer early.
The earlier the condition is found, the better the chances of surviving it.
You're also less likely to need a mastectomy (breast removal) or chemotherapy if breast cancer is detected at an early stage.
The main risk is that breast screening sometimes picks up cancers that may not have caused any symptoms or become life threatening. You may end up having unnecessary extra tests and treatment.
When will I be offered breast screening?
Breast screening is currently offered to women aged 50 to their 71st birthday in England.
But currently there's a trial to examine the effectiveness of offering some women one extra screen between the ages of 47 and 49 and one between the ages of 71 and 73.
You'll first be invited for screening between within 3 years of your 50th birthday, although in some areas you'll be invited from the age of 47 as part of the age extension trial.
You may be eligible for breast screening before the age of 50 if you have a very high risk of developing breast cancer. For more information, read having a family history of breast cancer.
If you're 71 or over, you'll stop receiving screening invitations.
You can still have screening once you are 71 or over if you want to, and can arrange an appointment by contacting your local screening unit or GP.
What happens during breast screening?
Breast screening involves having an X-ray (mammogram) at a special clinic or mobile breast screening unit. This is done by a female health practitioner.
Your breasts will be X-rayed one at a time. The breast is placed on the X-ray machine and gently but firmly compressed with a clear plate. Two X-rays are taken of each breast at different angles.
Breast screening results
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 no later than 2 weeks after your appointment. Following screening, about 1 in 25 women will be called back for further assessment but being called back doesn't mean you definitely have cancer. The first mammogram may have been unclear. About 1 in 4 women who are called back for further assessment are diagnosed with breast cancer.
Read more about understanding your results.