Physical changes in females

Breast development

The first physical sign of puberty in females is usually a firm, tender lump under the center of the areola(e) of one or both breasts, occurring on average at about 10.5 years of age.This is referred to as thelarche. By the widely used Tanner staging of puberty, this is stage 2 of breast development (stage 1 is a flat, prepubertal breast). Within six to 12 months, the swelling has clearly begun in both sides, softened, and can be felt and seen extending beyond the edges of the areolae. This is stage 3 of breast development. By another 12 months (stage 4), the breasts are approaching mature size and shape, with areolae and papillae forming a secondary mound. In most young women, this mound disappears into the contour of the mature breast (stage 5), although there is so much variation in sizes and shapes of adult breasts that stages 4 and 5 are not always separately identifiable.

Pubic hair


Pubic hair is often the second unequivocal change of puberty noticed, usually within a few months of thelarche.It is referred to as pubarche and the pubic hairs are usually visible first along the labia. The first few hairs are described as Tanner stage 2.Stage 3 is usually reached within another 6-12 months, when the hairs are too numerous to count and appear on the pubic mound as well. By stage 4, the pubic hairs densely fill the "pubic triangle." Stage 5 refers to spread of pubic hair to the thighs and sometimes as abdominal hair upward towards the navel. In about 15% of girls, the earliest pubic hair appears before breast development begins.

Vagina, uterus, ovaries

The mucosal surface of the vagina also changes in response to increasing levels of estrogen, becoming thicker and a duller pink in color (in contrast to the brighter red of the prepubertal vaginal mucosa).Whitish secretions (physiologic leukorrhea) are a normal effect of estrogen as well.In the next 2 years following thelarche, the uterus and ovaries increase in size, and follicles in the ovaries reach larger sizes.The ovaries usually contain small follicular cysts visible by ultrasound.


Menstruation and fertility


The first menstrual bleeding is referred to as menarche, and typically occurs about 2 years after thelarche.The average age of menarche in American girls is about 11.75 years.Menses (menstrual periods) are not always regular and monthly in the first 2 years after menarche. Ovulation is necessary for fertility, but may or may not accompany the earliest menses.In postmenarchal girls, about 80% of the cycles were anovulatory in the first year after menarche (about 13 years), 50% in the third (about 15 years) and 10% in the sixth year (about 18 years).However, initiation of ovulation after menarche is not inevitable, and a high proportion of girls with continued irregularity several years from menarche will continue to have prolonged irregularity and anovulation, and are at higher risk for reduced fertility.The word nubility is used commonly in the social sciences to designate achievement of fertility.

Body shape, fat distribution, and body composition

During this period, also in response to rising levels of estrogen, the lower half of the pelvis and thus hips widen (providing a larger birth canal).Fat tissue increases to a greater percentage of the body composition than in males, especially in the typical female distribution of breasts, hips, buttocks, thighs, upper arms, and pubis. Progressive differences in fat distribution as well as sex differences in local skeletal growth contribute to the typical female body shape by the end of puberty. At age 10 years, the average girl has 6% more body fat than the average boy, but by the end of puberty the average difference is nearly 50%.

Body odor and acne

Rising levels of androgens can change the fatty acid composition of perspiration, resulting in a more "adult" body odor. This often precedes thelarche and pubarche by 1 or more years. Another androgen effect is increased secretion of oil (sebum) from the skin. This change increases the susceptibility to acne, a characteristic affliction of puberty greatly variable in its severity.