Feeling unusually tired,
depressed, or nervous? Are you experiencing unexplained hot flashes,
changes in your menstrual cycle, or weight fluctuations? These symptoms
may be due to thyroid abnormalities. Dr. Judith Reichman was invited to
appear on “Today” to help us understand how the thyroid, the gland “that
rules the body,” works and what can happen, if it doesn’t function
properly.
If your thyroid is working as it
should, you won’t even realize that you have one. But if it isn’t,
you’ll definitely notice it. If the gland doesn't make enough hormones,
this is called hypothyroidism, a condition which causes your metabolism
to slow down. And if your thyroid makes too much, it will cause
hyperthyroidism, a condition that causes your metabolism (you guessed
it) to speed up.
What is the thyroid gland?
The thyroid is a butterfly-shaped gland found at the base of your
Adam’s apple. It secretes the hormones that influence the growth and
development of all your tissues, and regulates metabolism for your
entire body. These hormones, T3 (triiodothyronine) and T4 (thyroxoine),
are the only ones in your body that contain iodine. T4 is the primary
product of thyroid secretion. Once T4 is in the body’s tissues its
iodine portion is removed and it becomes T3. This is the biologically
active thyroid hormone that enters the cells and “does its thing.”
Production and secretion of the
thyroid hormones is controlled by another hormone, one that is produced
in the pituitary gland of the brain. This is aptly called the
thyroid-stimulating hormone (TSH). If the pituitary gland and the brain
center that controls its hormone production sense that there’s too much
T3 and T4 in the body, it ceases to make and release TSH. To determine
thyroid activity, we can either measure T3 and T4 levels in the blood or
we can measure TSH. Low levels of TSH will occur when T3 and T4 are too
high. High TSH means the pituitary gland is working hard to try to
elevate T3 and T4 levels in an inadequately responsive thyroid.
Who is at risk for
hypothyroidism?
In the U.S., the most common cause of hypothyroidism is a chronic
autoimmune disorder (that’s when the body’s antibodies attack the
thyroid gland) called Hashimoto’s disease. You’re at risk, if you have
a family history of thyroid disease, if your thyroid becomes enlarged
(this may be due to an inflammation called thyroiditis), if your thyroid
develops an irregular shape (due to a benign growth or goiter), or if
you have an autoimmune disorder such as lupus or rheumatoid arthritis.
Hypothyroidism is ten times more likely to affect women than it is men.
It occurs in four to 11 percent of all women. The female prevalence of
this disorder may have to do with our fluctuating hormones during
puberty, periods, pregnancy, and peri-menopause. Changes in estrogen and
progesterone may also trigger an autoimmune reaction so that antibodies
mistakenly attack and destroy thyroid tissue. This is more likely to
occur as we get older and after pregnancy (especially in diabetic
women). In as many as five percent of postpartum women, the thyroid may
undergo nonspecific inflammation (thyroiditis), and at least for a short
period of time, produce inadequate amounts of thyroid hormones. In some
cases, the thyroid remains slow (symptoms that mimic postpartum
depression may persist) and therapy is needed.
What are the symptoms of
hypothyroidism?
Lethargy
Weight gain from fluid retention
Cold intolerance
Constipation
Dry Skin
Coarseness and loss of hair
Memory and mental impairment
Decreased concentration
Depression
Irregular or heavy periods, or
infertility
High cholesterol
Symptoms that mimic those of
menopause
Hypothyroidism can directly affect
the central nervous system, cellular metabolism, utilization of glucose,
the inner thermostat, bowel function, and production of lipids. It can
cause the skin to lose water content. Because of the central nervous
system effects and the general slowing down of metabolism (and weight
gain), depression may follow. Appropriate amounts of the thyroid’s
hormones are necessary for regular ovulation, cycles, and fertility. An
insufficiency disrupts these functions.
How is the diagnosis made?
A simple blood test can checks the level of TSH. (Remember an
elevated TSH means that the pituitary is working harder to get the
thyroid to produce hormones.) Once an elevated TSH level is found,
other tests may be done including those for the T4, T3, and a free
thyroxin index or FTI (since most thyroid hormone is bound up by protein
as it circulates and only the unbound portion enters the cells to “do
it’s work”, this measures the unbound portion). The latter tests help
evaluate the actual working levels of thyroid hormones.
Who should be tested?
Currently, most of the endocrine societies recommend that a woman
have her TSH levels checked, if she is symptomatic, has a family history
of thyroid disorders, has an autoimmune disorder, such as diabetes, or
has high cholesterol. Or if she is in the early months of pregnancy and
has a previous history of autoimmune conditions or obstetrical
complications, such as recurrent miscarriage or early labor.
There is still some controversy as
to whether there should be routine prenatal screening in women with no
symptoms. There is a condition called pre-clinical hypothyroidism, where
the TSH levels are somewhat elevated, but the FTI and T4 levels have not
diminished below normal amounts. (In other words, the pituitary is
working harder to get the thyroid to do its thing, and it’s still
managing to do so). Yet, these women usually have no symptoms.
How do you treat
hypothyroidism?
It’s not clear that those individuals with sub-clinical
hypothyroidism should be treated. Many physicians believe that in the
long term, if TSH is moderately elevated, even in the absence of
currently low thyroid levels, a woman should be treated as soon as it’s
diagnosed. Others believe, that a wait-and-see attitude should be taken,
and that evidence-based medicine does not “bare witness” to an
indication to start therapy before thyroid levels fall. However, if a
woman has symptoms and/or her thyroid function is low, all physicians
agree that therapy should begin.
What about hyperthyroidism?
This is most commonly seen with Graves disease, an auto-immune
disorder in which an immunoglobulin (an immune protein) acts on TSH to
increase thyroid stimulation. This disorder affects about two percent of
women during their lifetime. And again, is much more common in women
than in men.
Common symptoms:
Heart palpitation
Heat intolerance
Nervousness
Insomnia
Breathlessness
Increased bowel movements
Light or absent menstrual periods
Fatigue
Trembling hands
Weight loss (or in some cases
because of nervousness and overeating and weight gain)
Muscle weakness
Hair loss
A staring gaze
Bulging eyeballs
Hyperthyroidism usually begins
between the ages of 20 and 40. It is diagnosed with a blood test for TSH,
which will be abnormally low. Further tests should then be run to show
that T3 and T4 also are elevated. An iodine thyroid scan should also be
performed to see if the cause is a single nodule, or the entire
thyroid.
Does hyperthyroidism have other
health effects?
The chief concern is cardiovascular. There is a much higher risk of
developing irregular heart beats, especially arterial fibrillation which
can lead to stroke and heart attack. Excess thyroid activity can also
cause bone breakdown; even sub-clinical hyperthyroidism can lead to
osteoporosis.
How is hyperthyroidism treated?
If your physician feels that your condition is due to a sudden
inflammation of the thyroid (you may have pain in the neck where the
thyroid is located or even have a mild fever), she may elect to simply
calm down the tremor and nervousness with beta-blockers and add
anti-inflammatory medications until the inflammation resolves (and the
symptoms dissipate). However, if overproduction of thyroid continues,
you will need specific drugs.
If the patient stops taking the
medication, the thyroid will overproduce hormones once again. As a
result, many physicians advise patients that their hyperthyroid
condition be “taken care of for good” with radioactive iodine. Thyroid
cells are the only cells in the body that can absorb iodine. When the
iodine is radioactive, it destroys these cells and their ability to
overproduce hormones. The most common side effect is that the thyroid
makes too little hormones, and the patient will need to take medication
for hypothyroidism. Finally, if the patient has a goiter or nodule that
is still overactive, surgery may be necessary.
Dr. Reichman’s bottom line:
Fatigue, weight gain, constipation, depression, memory problems, cycle
changes, nervousness, and heart palpitations are each very common
symptoms of thyroid problems. They may be caused also by psychological,
social and yes, medical situations. However, none of these symptoms
should be ignored. Thyroid testing may give you the answer and the
wherewithal for therapy that can change your life and health.
Dr. Judith Reichman, the “Today” show's medical contributor on
women's health, has practiced obstetrics and gynecology for more than 20
years. You will find many answers to your questions in her latest book,
"Slow Your Clock Down: The Complete Guide to a Healthy, Younger You,"
which is now available in paperback. It is published by William Morrow,
a division of HarperCollins.
