What is breast cancer?
Breast cancer is a cancer that starts in the breast. Breasts are made up of tissue, fat and glands. Sometimes, a small lump or change can start to develop in the breast. This may not cause pain, but it can cause changes in how the breast look or feel.
Finding breast cancer early can make it easier to treat. Breast cancer can happen to anyone, but it is more common as people get older.
Breast cancer usually develops because of a mix of things over time. Often there is no single cause.
Lifestyle and health factors that can increase risk:
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Drinking alcohol regularly. The more you drink, the higher the risk
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Being overweight, especially after the menopause
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Not being very active over many years
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Hormone medicines, such as HRT. The contraceptive pill can slightly increase risk while taking it
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Smoking may also play a part
Longer-term factors you cannot change:
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Getting older
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Family history of breast or ovarian cancer
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Inherited gene changes, such as BRCA1/BRCA2
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Dense breast tissue
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Starting periods early or going through the menopause later
Having one or more risk factors does not mean someone will develop breast cancer, but getting to know your body and being aware of changes is important.
You don’t need to panic, just notice what’s normal for you. Here are some things to look out for:
- A lump or thickening in the breast or armpit that feels new or different
- A change in the size or shape of a breast
- Changes to the skin on the breast, such as dimpling, redness or the skin looking like an orange peel
- Changes to the nipple including pulling in, a rash or crusting
- Fluid leaking from the nipple especially if it is bloody and you are not pregnant or breastfeeding
- Pain in the breast or armpit that does not go away
When to get advice
Speak to your GP practice if you notice a new lump or swelling, skin dimpling/redness, nipple changes, or nipple discharge (especially blood-stained).
Tests and next steps for breast cancer in women - NHS
For more information you can visit any of the links below.
Last reviewed: January 2026
