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.