HYPERTHYROIDISM
What is
hyperthyroidism?
Hyperthyroidism is a state in what the thyroid gland becomes
overactive. It is caused by several conditions. Graves'
disease, the most common cause of hyperthyroidism
(over-active thyroid), is an autoimmune disorder which causes
the body to manufacture and secrete excessive amounts of thyroid
hormone, resulting in an increased metabolic rate. The disease
is named for the 19th-century Irish physician, Robert Graves,
who first recognized the disease.
Other reasons for hyperthyroidism include
hyperactive thyroid nodules, de Quervain's thyroiditis, taking
too much thyroid supplements, and exposure to certain drugs or
chemicals.
How many people
suffer from Graves' disease?
In the United States, Graves' disease
afflicts approximately one million people.
Who is at risk for
developing Graves' disease?
While the cause(s) of Graves' are unknown,
the condition is sometimes familial, which means heredity may
play a role in who develops the disease. Evidence also suggests
that physical or emotional stress may be a factor in the onset
of Graves' disease. Women in their thirties and forties appear
to be especially vulnerable. Statistically, women are 15-20
times more likely than men to develop Graves' disease.
What are the
symptoms of Graves' disease?
The disease is characterized by increased
heart rate, heat intolerance, weight loss (often with increased
appetite), diarrhea or more frequent-than-usual bowel movements,
headache, restless over- activity, heavy sweating, irritability,
bad temper, irregular menstrual periods, sleeplessness and
weakness. Patients may also experience some of the eye changes
associated with Graves' disease, including burning, dryness, eye
protrusion, double vision and lid retraction.
Is hyperthyroidism
easy to diagnose?
Yes. If your physician orders the right
series of blood tests, the condition is easily diagnosed.
Unfortunately, because of the similarity of the symptoms,
patients suffering from Graves' disease are sometimes mistakenly
diagnosed as suffering from anxiety, depression, and
stress-related exhaustion. A thyroid panel of blood tests,
however, can easily distinguish these conditions from
hyperthyroidism.
What sort of
treatments are available for Graves' disease?
There are three methods of treatment
currently available for treating Graves' disease: antithyroid
drugs, radioiodine therapy and surgery.
What are
antithyroid drugs?
Antithyroid drugs interfere with the
formation of thyroxine (thyroid hormone) by blocking the organic
binding of iodine, thereby causing the symptoms of
hyperthyroidism to subside. The antithyroid drugs most commonly
in use today are propylthiouracil (PTU) and carbimazole (or
methimazole). In addition, your physician may also prescribe a
"beta blocker" called propranolol to help allay the increased
pulse rate associated with hyperthyroidism.
How often and for
how long must I take antithyroid medication?
Dosages of antithyroid drugs are tailored
to the needs of each patient. Some patients will thus take more
medication, while others will take less. Your endocrinologist
will set the correct dosage upon diagnosis and adjust it as
necessary throughout your regimen of therapy depending on your
hormone results. Length of treatment will likewise vary from
patient to patient. Although hormone levels usually return to
normal in about two to three months, most patients are kept on
drug therapy for eighteen months, others for two years. Once a
patient becomes euthyroid; that is, once the manufacturing of
thyroid hormone becomes controlled to acceptable levels (usually
by two to three months), the patient's dose will generally be
cut back to a smaller, "maintenance" dose. Antithyroid drugs are
very safe to take; a very small number of patients may develop a
mild rash.
Will beta-blockers
alone make me better?
No! While beta-blockers control some
symptoms of hyperthyroidism, they will do little to treat the
underlying disease. Taking beta-blockers alone can be extremely
dangerous, in fact, as they can mask the symptoms of Graves'
disease while the disease steadily worsens. For this reason,
they should be taken in conjunction with antithyroid drugs. Your
doctor will advise on this.
What is
radioiodine therapy?
Radioiodine is another method of treating
Graves' disease. Radioiodine is administered by mouth, usually
in liquid form. When given in a sufficient dose, it irradiates
the cells that participate in the Graves' disease process.
Is radioiodine
therapy safe?
Data compiled thus far from more than fifty
years suggests that it is. Radioiodine has been used to treat
hyperthyroidism since 1948, and doctors regard it as a safe and
effective means of treating Graves' disease. A few doctors,
however, still prefer to restrict its use to patients beyond
childbearing age. Radioiodine is always contraindicated during
pregnancy. Women are advised to avoid pregnancy for at least six
months after taking radioiodine. It is usually a one-time
treatment. It is usually given to patients who relapse after a
course of drug treatment.
What about
surgery?
In some instances, patients and their
doctors may feel that Graves' disease can be best treated by
surgery to remove most of the thyroid gland. While generally
effective, surgery is expensive and, in some instances, risky.
Surgery is thus usually reserved for those patients who are
unable to take antithyroid drugs and who refuse radioiodine
treatment.
What's this about
Graves' disease affecting the eyes?
In some patients, ophthalmopathy (eye
changes) are an unfortunate effect of Graves' disease. These
changes may precede, accompany or follow thyrotoxicosis and can
include light sensitivity, excessive tearing, proptosis
(protrusion of one or both eyes), pain, swelling of the
eye-lids, diplopia (double vision), dryness, and loss of visual
acuity. There is no definitive therapy for these eye changes.
However, some patients have found methylcellulose eyedrops, a
low-sodium diet, and elevating their heads while sleeping to be
helpful. Steroid therapy may be therapeutic in particularly bad
cases, as may radiation therapy to the posterior portion of the
eye and surgical decompression. Fortunately, such severe cases
are rare.
Didn't George Bush
have Graves' disease?
Yes, former U.S. President George Bush
suffered from the disease while he was president, as did his
wife Barbara. Statistically, in fact, the Bushes are something
of a medical marvel. Graves’ disease is rarer in men than in
women. It is nearly unheard of for a husband and wife to both
suffer from Graves' disease.
Complications of Graves' disease
In patients who have multiple successive
relapses, there is a risk of developing heart failure. Also if
the hyperactivity is very severe, the patient may develop a rare
state called thyroid crisis. The latter is characterized by
confusion, elevated temperatures, changes in conscious level,
heart problems. It is a serious medical emergency and treatment
in an intensive care setting is usually recommended.
Treatment of
Graves' disease during pregnancy
Patients with Graves' disease are often
women in their reproductive years. If hyperthyroidism develops
during pregnancy, it is safe to continue antithyroid drugs. Drug
treatment is needed to stabilize the condition and reduce the
risk of a miscarriage. Often during the last trimester of
pregnancy, the hyperthyroidism disappears and drug treatment may
be safely discontinued. However there is a significant risk of
relapse following delivery of the baby.
It is usually safe to breastfeed while
continuing antithyroid drug treatment.
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