What Is It?
A hot flash is an episode of vasomotor instability. According to
current theories, hot flashes are probably due to a menopause-related
drop in the body's blood level of estrogens (female hormones). This
estrogen drop appears to trigger changes in the hypothalamus, an area of
the brain that regulates "unconscious" body functions,
including body temperature. A temporary resetting of the body's core
temperature to a lower value results in an effort, by the body, to
release heat. One mechanism to do this is the dilation of blood vessels,
particularly those near the skin of the head, face, neck and chest.
Hot flashes affect approximately 85 percent of women during the years
immediately before and after menopause, which usually occurs around age
51. Hot flashes may begin as early as two to three years before the last
menstrual period, and persist for six months to 15 years (average of two
years) after menstruation ends. Some women have only a few episodes a
year, while others have as many as 20 episodes a day. Hot flashes occur
in women who experience natural menopause, as well as in those who
undergo surgical menopause (estrogen drop due to removal of the ovaries)
or medical menopause (low levels of estrogen due to medications such as
gonadotropin-releasing hormone agonists or danazol).
Although hot flashes are usually considered to be a "female
problem," men may also experience hot flashes if their levels of
testosterone (male sex hormone) suddenly and dramatically drop. For
example, hot flashes occur in 75 percent of men with prostate cancer who
are treated with orchiectomy (surgical removal of the testes) or
medication to decrease testosterone levels.
Also, symptoms that mimic hot flashes may occur in both men and women
who suffer from a tumor of the hypothalamus or pituitary gland, certain
serious infections (especially tuberculosis or HIV), alcoholism or
thyrotoxicosis (extremely high levels of thyroid hormone). Symptoms that
are similar to hot flashes may also be a side effect of the food
additive monosodium glutamate (MSG), or of certain medications,
particularly nitroglycerine, nifedipine, niacin, vancomycin and
calcitonin.
Symptoms
A hot flash begins as a sensation of intense warmth in the upper
body, followed by skin flushing (redness), drenching perspiration, and a
finally a cold, clammy feeling. Typically, these symptoms begin at the
head and spread downward toward the neck and chest, and last anywhere
from 30 seconds to five minutes (average is four minutes). Hot flashes
may be accompanied by heart palpitations, a "pressure" feeling
in the head, or feelings of vertigo, faintness or weakness. When hot
flashes occur during the night, they can cause insomnia, resulting in
poor concentration, memory problems, irritability, and exhaustion during
the daytime.
Because hot flashes are related to a drop in estrogen levels, a woman
who is experiencing hot flashes typically has other symptoms that are
also caused by decreased estrogen. These may include vaginal dryness,
itching and irritation (which may produce discomfort during
intercourse); thinning of the skin, with loss of skin elasticity; and
urinary incontinence, due to a relaxation of ligaments that support the
pelvic organs. There may also be episodes of headaches, nervousness,
irritability and mood swings.
What Your Doctor Looks For
After noting your age, your doctor will ask you whether you are still
having regular menstrual periods. If you are not, the doctor will want
to know the approximate date of your last period. If you are still
menstruating, the doctor will want to know whether there is anything
unusual about the timing of your periods or the amount of blood flow. In
addition, your doctor will ask whether you are also experiencing any of
the other symptoms that may be related to decreased estrogen, such as
vaginal dryness, pain or discomfort during intercourse, or urinary
incontinence. Finally, your doctor will review your medical history,
your gynecological history and the types of medications you are taking.
This is to rule out the possibility that your hot flashes are a symptom
of a medical or gynecological illness, or a side effect of medication.
Expected Duration
In most women who undergo natural menopause, hot flashes subside
within two to five years after the last menstrual period . In a minority
of women, however, they may persist for eight years (12 percent of
cases), or as long as 15 years (10 percent of cases).
Also, there is some evidence that women who experience surgical
menopause have more severe hot flashes for a greater number of years
than those who have experienced natural menopause .
Treatment
Doctors treat hot flashes by prescribing estrogen replacement therapy
(ERT), usually together with progesterone if the patient still has her
uterus. Estrogen may be taken orally as a pill, or administered through
a transdermal patch or vaginal ring. In patients who have not had a
hysterectomy, progesterone is added to ERT to decrease the small risk of
uterine cancer in women who receive ERT alone.
If a woman cannot take ERT, or if ERT is not effective, alternate
medications may be prescribed to treat hot flashes, including clonidine,
lofexidine, methyldopa, veralipride or antidepressants such as
paroxetine (Paxil), fluoxetine (Prozac) and sertraline (Zoloft). For
women who have undergone surgical menopause and have unusually severe
hot flashes, new studies have shown that a combination of estrogen and
androgen may be effective.
Several nonprescription "natural" herbal remedies are also
available to treat hot flashes. So far, research studies suggest that
products containing soy isoflavones may be the most effective of these
nonprescription treatments. Although some women also use dong quai and
wild yams, there is currently no evidence to prove that these herbals
work against hot flashes. Additional new evidence may indicate that the
herb maca may be very effective in reducing or stopping hot flashes and
further studies are needed.
