Breast development

Breast development is a natural and important stage in the growth of girls.

• Unlike other mammals, human females are the only ones who develop full breasts long before they are needed to nurse their offspring.
• Breast development occurs in distinct stages, first before birth, and again at puberty and during the childbearing years.
• Changes also occur to the breasts during menstruation and when a woman reaches menopause.

Three phases of development

The development and kinds of breast changes that take place are directly related to age.

• Lobule development — between the ages of 10 and 25
• Glandular development — between the ages of about 13 and 45
• Involution, or shrinkage of the milk ducts — begins at about age 35

Center for Young Women’s Health

Children’s Hospital Boston has created a site that’s just for young women. You can find health guides about breast health and other topics written just for you, as well as quizzes, our blog and even a cookbook full of fun, tasty and nutritious recipes.