Updated: SEPTEMBER 19, 2016
Thelarche is the medical term for the start of the development of female breasts.
The term comes from a combination of two ancient Greek words: thele, which means nipple, and archaios, meaning beginning.
As the tiny bumps of thelarche are known informally as breast buds, this process is also known as breast budding.
More About Thelarche
Breasts grow slowly, starting as just tiny bumps or breast buds underneath the nipples and areolas. This occurs due to fat deposits growing in the chest, periductal connective tissue expanding, and the ductal system elongating, branching, and thickening. These changes are influenced by estrogen, prolactin, and the growth hormone.
The breasts may grow together or unevenly. The breasts may feel itchy, tender, or achy as they’re coming in. It’s common for girls to feel self-conscious about their changing body during thelarche.
Thelarche typically occurs at the onset of puberty, when a girl is between 9 and 13 years of age. It is usually the first symptom of puberty, occurring at the start of a rapid period of physical growth. However, in some cases a girl develops breasts much earlier than this. This phenomenon is known as premature thelarche. During premature thelarche, a girl’s breasts grow without any other signs of sexual maturation.