The bleeding is most common during
the first few months of taking the pill
and is caused by incomplete suppres-
sion of the monthly buildup of the
(lining of the uterus). (See
Either of the two mammary glands,
which, in women, provide milk to
nourish a baby and are secondary
The male breast is an
immature version of the female breast.
DEVELOPMENT AND STRUCTURE
At puberty, a girl’s breasts begin to
develop: the areola (the circular area of
swells and the nipple enlarges. This is
followed by an increase in glandular tis-
sue and fat.
The adult female breast consists of
between 15 and 20 lobes of milk-secret-
ing glands embedded in fatty tissue. The
ducts of these glands have their outlet
in the nipple. The areolar skin contains
sweat glands, sebaceous glands, and hair
follicles. Bands of fine ligaments deter-
mine the breast’s height and shape.
The size, shape, and general appear-
ance of a woman’s breasts may vary
throughout the menstrual cycle, during
pregnancy and lactation, and following
During pregnancy, the hormones
which are secreted
by the ovaries and placenta, cause the
milk-producing glands in the breasts to
develop and to become active. These
two hormones also cause the nipples
Just before and immediately after
childbirth, the glands in the breast pro-
duce a watery fluid known as
The production of this fluid is replaced
by milk production a few days later.
Milk production and release are stimu-
lated by the hormone
A collection of pus in the mammary
gland, usually in a woman who is lactat-
ing (producing milk). Breast abscesses
develop if acute
of the breast) is not treated promptly
and occur most commonly during the
month after a woman’s first delivery.
The initial symptoms of a breast
abscess are the same as those of acute
mastitis. The abscess develops in one
area, which becomes very firm, red, and
extremely painful. Treatment involves
(withdrawal by suction)
of the pus
using a needle and syringe. In rare
cases, surgical drainage may be needed.
A woman’s familiarity with the appear-
ance and feel of her breasts, which
allows her to recognize both normal
and abnormal changes. Doctors recom-
mend that women develop “awareness”
in order to improve the chances of
at an early stage.
The common name for the
front part of the
Breast cancer is the most common type
of cancer in nonsmoking women and
the second most common type, after
lung cancer, in women who smoke.
One woman in every 12 who live to old
age will develop breast cancer at some
point in her life. Breast cancer can also
rarely develop in men. The advancement
of techniques for early diagnosis and
treatment of breast cancer has improved
overall survival rates.
Current theories regarding the causes of
breast cancer are focused on hormonal
and genetic influences. However, the
principal risk factor is age, with a
woman’s chances of developing the dis-
ease doubling every ten years of her life.
The incidence of breast cancer is
known to be raised in women whose
menstrual periods began at an early age
and in those whose
to commence. The risk is also higher in
women who did not have children or
those who had their first child late in
life. Women whose mothers or sisters
have had breast cancer are also at an
increased risk. Diet may also play a part;
breast cancer is more common in coun-
tries in which the typical diet contains a
lot of fat. Studies have shown that
mone replacement therapy (HRT)
chances of developing
breast cancer; the risk increases with the
length of time that HRT has been taken.
THE FEMALE BREAST
The breast is made up of lobes of glands set
in fatty tissue, the ducts of which have their
outlet at the nipple. The areola contains
sweat glands, sebaceous glands,
and hair follicles.
An X-ray of a healthy breast.
The dense white areas are fibrous
tissues that support the fat nodules.
P e c t o r a l
m u s c l e