Breasts, nipples and areolae are evident from the day we are born, on both girls and boys. There is very little actual breast tissue present at birth, although a few days after birth it is not at all unusual for babies to produce what is referred to as 'witches milk' from their nipples. This is said to be caused by the strong influence of the mother's hormones just before delivery, and then the milk is not present again until other conditions later in life cause lactation to start up.
Females reach a certain time during which their breasts begin to develop further. Along with the appearance of pubic hair (and other "secondary sexual characteristics"), this usually begins one or two years before menarche' (first menstrual period). The early development of her breasts are usually the first visual signs others notice that indicats a young girl is starting to mature. When breasts develop they go through five individual 'stages' that have been described by Dr. J. M. Tanner, a British doctor. These "Tanner Stages" are used to indicate relative change that occurs in female breast development, and may tend to be a little ambiguous. Consequently, they are open to the interpretation of the observing physician.
Stage One technically starts when the hypothalamus in the brain secretes gonadotropin-releasing hormone (GnRH), stimulating the pituitary gland (also in the brain) to secrete follicle-stimulating hormone (FSH) into the blood circulation. That stimulates the ovaries to produce estradiol. Visually, Stage One is defined as that which is happening from birth until some enlargement occurs in the nipples and areolae. The breast glandular tissue is referred to as a breast "bud" at this stage. All of the components of the breast are there, but they are quite small, as they have not yet developed. Development in the female will usually begin to occur at the onset of puberty. A male's breast will usually remain in this stage throughout his life.
Stage Two is that breast development which occurs after the breast bud has begun to change and shows some enlargement. A small mound will begin to develop under the nipple. The nipples will increase in size, often causing some embarrassment due to their appearance under clothing. The areolae will begin developing to a larger size and may start to slightly darken in color. The nipples become very sensitive at this time, and may have more sensations. During stage two is when the first menstrual flow (menarche') usually occurs, about two years after breast development begins.
Stage Three is a little difficult to describe. Specific breast features are somewhat arbitrary, and stage differentiation is subject to the professional that is making the judgment. Stage three is obviously between stages two and four, and general overall enlargement of the breasts, nipples and areolae occurs. Professional experience is usually used to decide where stage three starts and finishes. During this stage the breasts will often take the shape of simple cones or funnels.
Stage Four may often be indicated by the formation of a secondary
swelling just under the areolae. It is almost as if a second breast bud
is developing on the front of the existing breast. This can be seen during
the early teens, or as late as the early twenty's.
The beginning of breast development (when a young woman enters stage two) is considered one of three signs of the start of puberty. It is common for this to occur between the age of 9 years and 14 years. Some girls may wait until as late as 18 years or more, while some start earlier than nine. If she starts earlier than 8 years old, she is often considered to be experiencing precocious puberty. In the past twenty or so years, extremely early breast development was controlled with Tamoxifen, an estrogen blocker that is now being used to reduce the chance of breast cancer returning in women who are survivors of that disease. Other medications tried were Lupron and Lupron Depot. Before making any decisions on "treating" a girl that appears to be developing at too young of an age, it is recommended that you read "Early Puberty in Girls", by Doctor Paul Kaplowitz, m.D., Ph.D., Ballantine Books ' Random House publishing Group, 2004, ISBN# 0-345-46388-9 (www.ballantinebooks.com). Many young girls are treated for premature breast enlargement when they really may not require any attention at this time. We have become so attentive to "breast-culture" that we tend to over-react more often then not.