Premature thelarche refers to the early onset of breast development in girls, usually before the age of 8. Other synonyms for this medical condition include precocious puberty, early puberty, or premature breast development. In some cases, the condition may be accompanied by the early onset of menstruation, known as premature menarche. While early breast development is not always a cause for concern, it is important to consult with a medical professional to determine the underlying cause and potential treatment options. Some of the potential causes may include hormonal imbalances or genetic factors, and treatment options may include medication or lifestyle changes.