Under 20 • Breast Cancer Foundation NZ

Breast awareness

Taking care of your breast under 20



Breast cancer is extremely rare in adolescent and teenage girls, but many young girls are worried that some of the changes going on in their breasts might mean they have cancer.

It can be uncomfortable and embarrassing talking to someone else about changes happening in your body. You might notice that you and your friends are growing in different ways, so it’s helpful to understand what’s happening and what you might expect, so that you don’t have to worry unnecessarily.

Breast development

Breasts usually start to grow at around the age of 9 to 11 years but it’s also normal for it to happen earlier or later.


  • A small bump called a breast bud will develop under the nipple and areola (the darker skin around the nipple). It may grow first on one side then the other. This stage can be uncomfortable for some girls and there is often some tingling or aching as the breast bud grows.
  • Your breasts will gradually get bigger as the fatty tissue grows and glandular tissue develops. This is the tissue which is capable of producing milk after the birth of a baby.
  • The nipples will grow and become more prominent. They may become tender for a while and the areola will enlarge.

The process of development takes a period of years and is usually finished by the age of 17 or 18.

Are my breasts normal?

One of my breasts is bigger than the other.

It’s quite common for breasts to be slightly different in size or to have one which sits slightly higher or lower than the other. While they’re developing they might also grow at different rates, although they usually look about the same by the end of the process.


My breasts feel lumpy

As breast tissue continues to develop, your breasts may feel generally lumpy and tender. This is due to fluctuating hormones and will usually settle down over time.

My nipples don’t point outwards

In 10-20% of girls, the nipples may be flat or be drawn inwards on one or both sides. This is normal and does not create any health problems. It might have been present from birth or it may occur as the breasts develop.

My nipples don’t look the same

Nipples come in many different sizes and shapes. They may point up, down, or away from each other. They can be pale or dark, large or small, and may not look completely alike.

I have little lumps around my nipples

The skin on the areola (the dark area around the nipple) contains little glands known as Montgomery’s tubercles. They look like little bumps or pimples on the skin and they produce a fluid which moisturises the skin of the areola and nipple.

I have hair around my nipples

Some girls will notice a few hairs growing around the edge of the areola. This is quite common and if it bothers you it can be removed by cutting or plucking the hair.

My breasts hurt or feel uncomfortable

As breasts develop, the changing hormone levels can cause some breast discomfort and this is normal. Once you are having periods you might find the time before your period starts is when your breasts feel particularly tender. This usually settles down when your period is over. Some girls will have discomfort which is not related to their menstrual cycle. It’s important to have a well-fitting supportive bra to help with any discomfort.

I’ve got a red spot/area on my breast

Often this will be caused by an infection in the skin of the breast. If it isn’t going away by itself, see your GP.

I can feel a distinct breast lump

Occasionally a benign (not cancerous) condition can produce a lump in the breast. The most common cause of a breast lump in young girls is a fibroadenoma which tends to feel rubbery and mobile in the breast. This is a harmless condition but all lumps should be checked by a doctor.

Could I get breast cancer?

Breast cancer in young girls is extremely rare and the majority of breast cancers occur in women over the age of 50. In your early teenage years, you shouldn’t worry too much about your breasts; however, there are some things you can do to reduce your risk over your lifetime.

  • Maintain a healthy body weight. It’s important to develop good patterns of healthy eating early in your life. Avoid junk foods and eat plenty of fresh fruits and vegetables.
  • Regular exercise also reduces your risk. The World Health Organisation recommends that children and youth (up to 17) should have at least 60 minutes of moderate to vigorous-intensity physical activity daily. It’s important to continue to exercise regularly throughout your life.
  • Avoid alcohol and smoking as both of these contribute to cancer risk.

It’s never too early to start adopting a healthy lifestyle. From the age of 20 you should also start checking your breasts regularly so that you know what they normally feel like. That way any changes can be picked up early and checked out by your GP.