It’s not a tumor or a cyst… your daughter is getting breasts!

It’s not a tumor or a cyst… your daughter is getting breasts!

Not too long ago, a mother brought her nine-year-old daughter into my office, concerned about a hard bump growing under one of her nipples.  “I know she’s supposed to eventually get breasts,” the mom explained, “but it seems a little early.”  The mom wanted to make sure the bump wasn’t something more serious like a tumor. 

In fact, the first signs of breast development can appear as early as eight years old and that hard bump under the nipple is exactly what you would expect.  Here’s some other facts about your daughter’s breast development that should help you understand her changing body. 

On average, girls breasts start developing between the ages of 8 and 13.
Thelarche (Thee-lark-ee) is the medical term for the beginning of breast development and is caused by hormones released by the ovaries during puberty. These hormones (estrogen) cause the fat and other tissues in your breasts to accumulate and grow. For 90% of girls, this is the first sign of puberty.  

The earliest sign of breast development is the development of breast buds.  
A breast bud is a firm, round, tender and sometimes itchy lump under the nipple of one or both breasts.  

Breast asymmetry is common during breast development.
In many adolescents, budding breasts may not begin to develop evenly. Typically, by age 18 the size difference should be less obvious but slight differing breast size is completely normal even in some adult women. It's also common for breast buds to be tender or sore. When breast buds first emerge, they can be tender and sore.  This tenderness will go away as the breast continues to develop. The skin can also be itchy as it starts to stretch but this too will subside. 

What to expect after breast buds…?
After the first sign of breast buds, breasts will show an increase in size within 4-6 months. On average, it takes about 4-5 years for full breast development after the start of thelarche, with most girls usually fully developed by 18 years of age. As breasts develop, they become rounder and fuller.  The areola may get darker and larger, and the nipple may start to stick out.

Breast size is largely determined by heredity.
Breasts come in all shapes and sizes. There is almost no size that is considered abnormal.  Your breast size is primarily determined by heredity. Because breasts contain fat cells, a girl’s breasts size can increase with weight gain. 

Just because she has breast buds doesn’t mean she’s getting her period right away.
On average, it takes 2-3 years from the start of thelarche (breast bud development) to menarche (first period). 

It may be normal, but it can still feel awkward! 
Help your daughter feel more comfortable about her changing body.  Share your own experiences getting boobs and buy her bras that cover and protect her breast buds (we recommend lycra bralettes and bras to start). 
This is just one piece of the puberty puzzle and a reality of our girls growing into young women. You’re not alone. Girl Factor is here for you, and your Girls throughout the journey so stick with us and stay tuned for what’s to come. 
Dr. Inga Sazan is a Board Certified Pediatrician and a Fellow of the American Academy of Pediatrics. 

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