Take a moment and think about your breasts. What’s the first thing that comes to mind? If you are like most women, you have a definite opinion about them. And you’re not happy. You think they are too small, too large, a bit uneven, or not firm enough. Many women define their sexuality by how their breasts look to them and how they think they look to their sex-ual partners. Surveys show that more than 40% of women, when asked how they felt about their breasts during puberty, reported they were embarrassed, shy, worried, or unhappy.
Wouldn’t it be wonderful if women learned at an early age to understand and appreciate this part of their anatomy?
Many women are afraid of their breasts: afraid of breast cancer, fearful of mammography, uncertain about how to examine themselves for lumps. They don’t completely under-stand why their breasts go through so many changes every month and what those changes mean, except perhaps that they have something to do with hormones. They eye their breasts with trepidation whenever something “unusual” occurs, such as tenderness, pain, nipple discharge, or lumps, not knowing if they should be worried (in most cases, no, but you should be examined), and worrying nonetheless.
This series of posts helps you replace worry with knowledge.
With knowledge comes understanding, and with understanding comes the power to take control of your breast health. And that knowledge begins with the basics of breast development and function so that you can recognize what is normal, what is not normal, and what you can do about it.
Breast Basics: What You Need to Know
The female breast is the object of sexual desire, a source of nutrition, and a thing of beauty, but the anatomical definition is much more mundane: it is a modified sweat gland composed primarily of fat and glandular tissue. The size, shape, and health of your breasts are the product of your heredity, hormones, environment, and lifestyle. Heredity plays a large role in determining the appearance and health of your breasts.
There’s nothing you can do about your heredity: if your genes are coded for big breasts, you will naturally have big breasts. You can, however, have some effect on your hormone levels by controlling, to a large extent, your environment and lifestyle.
The Budding Breast
Female breast development begins in the womb at 6 weeks after conception. As the fetus develops, the female hormones estrogen and progesterone lay the groundwork for breast development. Estrogen stimulates the growth of ducts in the breasts, and both estrogen and progesterone promote devel-opment of the milk-producing glands, called lobular glands.
At about the same time, the mother is producing hormones that assist in breast growth, including insulin, adrenal steroids, growth hormone, prolactin, thyroid-stimulating hormone, and luteinizing hormone.
The breast tissue, or mammary gland, is the first portion of the breast to develop. Along the area from the groin to just above the armpit, a parallel set of glands form on the fetus.
This “milk ridge” disappears by week 9 of the pregnancy except for one pair of glands, which later develop into breasts. On rare occasions, one or two paired glands along the ridge remain, and an infant is born with an extra nipple. This is known as polymastia, and often appears as a mole.
Aside from a slight nipple discharge called “witch’s milk,” which occurs in 80 to 90% of all infants during the first few days of birth, breast development lies dormant for the next 10 to 12 years. Then estrogen levels rise, which causes the hormone receptors in the breasts to stimulate the growth of the milk glands (see figure below). For some girls, this is accompanied by itchiness or slight pain under the nipple. This initial step into puberty typically begins before a girl’s first menstrual period.
Once menstruation begins (usually between years 11 and 15), a girl’s breasts respond to the release of hormones from the brain, adrenal glands, and ovaries. Breast tenderness and swelling are the two most common symptoms during this time.
The Reproductive Years
Breast changes are associated with the menstrual cycle. When a young woman begins menstruation, all of the hormones involved in the process—follicle-stimulating hormone (FSH), estrogen, luteinizing hormone (LH), and progesterone—prepare the breasts for the possibility of nursing.
During the first half of the cycle, approximately 14 days before ovulation, FSH is released from the pituitary gland. FSH prompts the production of estrogen by the follicles, which are the eggs enveloped in a sac on the ovaries. As the blood’s estrogen level rises, it causes the milk glands to swell, making the breasts firmer and larger. Once estrogen reaches a high level, FSH stops its work and LH takes over. Estrogen and LH initiate ovulation,which is when the follicle releases a mature egg. The second half of the menstrual cycle has begun.
As the egg travels down the fallopian tube on its way to a potential pregnancy, the ovary produces another hormone, progesterone.Progesterone prepares the breasts for breast-feeding and prompts the lining of the uterus to transform into an environment rich in blood vessels and glandular tissue for the approaching egg.
The most direct effect of hormones on the breasts is caused by the combination of estrogen and progesterone, which initiate an increase in ductal and lobular tissue, respectively. These changes result in the breast tenderness and swelling that affect many women during their menstrual cycle. They may also notice that their breasts feel lumpy during the second part of their cycle, which is normal. To alleviate any fear you have about these lumps, examine your breasts periodically through out your menstrual cycle. If you notice your breasts are lumpy or lumpier during the second part of your cycle, you’ll know the lumps are a normal part of your cycle.
If fertilization does not occur, estrogen and progesterone levels decline and menstruation begins. Without the high levels of these two hormones, breast swelling, tenderness, and lumpiness disappear. If, however, pregnancy is initiated, the breasts will undergo changes that prepare them for breast-feeding. Pregnancy and breast-feeding are covered in depth in this post.
Perimenopause and Menopause
For most women, their menstrual periods begin to change in regularity in their late 30s to early 40s as estrogen and pro-gesterone levels decline. This period is commonly known as perimenopause.Internally, the supply of follicles is so low that they are unable to produce sufficient estrogen to maintain menstruation. As menstruation decreases (which often occurs gradually over months or even years), other body changes take place, including breast soreness and the formation of lumps or cysts in the breasts. Most of these lumps are benign and occur because the breast tissue shifts during this stage of life. Other symptoms of perimenopause include dry, flushed skin and backache.
Some women skip perimenopause and directly enter menopause,which is when menstrual flow stops completely.
Unless you are on hormone replacement therapy, the dramatic decline in estrogen and progesterone causes the breast tissue to soften and thin. Fat then takes its place. Eventually follicle production of estrogen ceases completely and the role of the adrenal gland, which produces the hormone androgen (which is converted to estrogen), takes over what-ever small amount of estrogen production occurs in the body.
Around age 70, however, this alternate supply of estrogen also stops.