What causes breast growth during puberty?
Breasts grow mainly because of hormones, especially estrogen. During puberty your body makes more estrogen, which tells the breast tissue to grow and to accumulate fat. This is a normal part of maturing your body for reproduction.
What to expect and the typical timeline
- Breast buds: The first sign is small swellings under the nipple area.
- Over the next months and years, the breasts grow, change shape, and may feel tender.
- Often one breast grows a little before the other; asymmetry is common and usually becomes less noticeable over time.
- Breast development can continue for several years. Most people finish puberty between ages 14 and 17, but timing can vary.
- Other puberty changes (height growth, body hair, and sometimes periods) may happen around the same time.
Comfort and care tips
- Wear a well-fitting, comfortable bra. If you’re unsure of your size, consider getting measured or trying different sizes at a store. Many teens start with soft cotton or sports bras.
- Avoid tight or underwire bras if they cause discomfort.
- Keep the skin around the breasts clean and moisturized; normal puberty can bring temporary skin changes.
- Mild tenderness or soreness around your period is common and usually temporary.
When to talk to a healthcare provider
Reach out to a parent or guardian and a healthcare provider if you notice anything unusual, such as:
- A lump that doesn’t go away or keeps growing
- Severe or persistent pain
- Redness, warmth, or fever around the breast
- Nipple discharge that is bloody, green, or occurs outside of normal puberty
- Breast development that seems unusually slow or stops very early
Remember, every body grows at its own pace. It’s okay to ask questions with a trusted adult or doctor if you’re unsure about what you’re experiencing.