Puberty in girls is the transition from childhood to adulthood: a predictable sequence of events, each judged against population norms, that ends in reproductive capacity and adult stature. The events are named with the suffix -arche, “beginning”: thelarche is the start of breast development, adrenarche the start of adrenal androgen production and menarche the first menstruation. Their timing varies with ethnicity and between individuals, and it can depart from the normal course in either direction, earlier or later than expected.
Puberty is best understood first as it should happen, from the growth that produces adult height to the ordered appearance of these events, and then through what changes when the timing is wrong.
The normal course
- Somatic Growth and Its Determinants in Puberty — the first phase of puberty: the genes that set stature, and the hormones that drive the growth spurt and close the growth plates (the growing ends of the long bones).
- Normal Physiology of Puberty in Girls — the vocabulary and the sequence of thelarche, adrenarche and menarche, their timing, and when the hypothalamic-pituitary-ovarian axis (the hypothalamus, the pituitary gland and the ovaries, linked by their hormones) becomes mature.
Abnormal timing
Abnormal timing is defined against the normal range, and those definitions lead to a classification that the clinical notes on early and late puberty then use. The gonadotropins, LH and FSH, are the pituitary hormones that command the gonads; whether they drive early puberty is what separates its central from its peripheral forms.
- Abnormal Puberty in Girls: Definitions and Classification — how abnormal timing is defined, the age cutoffs that follow from it, and the central-versus-peripheral framework used to classify precocious puberty.
- Precocious Puberty in Girls — the classification and causes of early puberty, how the diagnosis is confirmed, and the suppression of the pubertal axis.
- Delayed Puberty in Girls — the causes of late puberty, how the underlying failure is identified, and how puberty is induced.
Start with somatic growth and read in the order listed.