Think of the thyroid as the body's regulator. It does its
job by releasing 2 thyroid hormones, T3 and T4, that affect most organs of the body
including the heart, brain, liver, kidneys, skin..., even the growth of your hair. These
hormones help regulate the heartbeat, body temperature, how quickly a person burns
calories, how swiftly food moves through the digestive tract, and more.
Normally, the thyroid doles out just the right amount of
thyroid hormone to keep these processes humming smoothly. But, it may become overactive
and pump out too much hormone, or underactive and pump out too little. Either way, the
abnormal thyroid hormone levels can profoundly effect the body's metabolism.
WHAT CAN HAPPEN BECAUSE OF AN OVERACTIVE THYROID?
For several weeks, Barbara Bush suffered what she assumed
was just stress. Although Mrs. Bush inexplicably lost 18 pounds, she wasn't particularly
worried. When her eyes became irritated however, she turned to her doctors What the First
Lady eventually learned was that she is one of 7,000,000 Americans who suffer from one of
two common thyroid problems. Barbara Bush's thyroid was too active - a condition called
hyperthyroidism or thyrotoxicosis, also known as Graves' Disease.
To explain what thyrotoxicosis is like, picture yourself
sitting in a car that is parked and idling quietly in the driveway. Now imagine pressing
the accelerator until the engine is revving up in neutral, but you are still going no
place. The engine is getting hotter and hotter, straining more and more, you are burning
up more and more gasoline but you are still going no place. About 2,000,000 Americans are
similarly revved up. Their thyroids pump out excess hormones, which push their metabolism
into overdrive.
This is hyperthyroidism, or thyrotoxicosis, and it may
produce diverse symptoms: frequent loose stools, heightened sensitivity to heat, excessive
sweating, weight loss, fatigue, muscle weakness, nervousness, irritability, insomnia, and
tremors. Another symptom, a rapidly pounding heart when you are at rest, can be especially
serious. It can intensify chest pain in people with heart disease and can even precipitate
a heart attack.
People who suffer untreated hyperthyroidism sometimes
have a wide eyed look caused by thickened tissues behind the eyeballs that push the eyes
forward and can threaten vision. They may experience tremors, palpitations of the heart,
increased sensitivity to heat, hot moist skin, constant thirst and irregular periods along
with irritability
The 18 pounds that Mrs. Bush lost in two months without
dieting is a classic sign of the hyperthyroidism spoken about. She also developed eye
problems. Graves' disease (which is the type pf hyperthyroidism that she had) is named
after the 19th century physician, Robert Graves who first described many of the features
of the illness. It is the most common type of hyperthyroidism accounting for much more
than half of all cases. It is a very serious disorder which can frequently be fatal if
left untreated.
WHO DOES GRAVES' DISEASE AFFECT?
Graves' disease affects mainly women, especially those
aged 30-55. It is an autoimmune disease in which white blood cells produce antibodies,
little darts that usually attack and destroy germs and other invaders, but instead are
directed towards the thyroid gland causing it to produce too much thyroid hormone or
towards the eyes, causing the eye muscles and tissues to swell and push the eyeball out of
the socket.
Symptoms include bulging of the eyeball, painful pressure
and persistent double vision. This pressure and bulging out can lead to blindness if it is
not corrected.
HOW DO YOU TREAT GRAVES' DISEASE?
Treating Graves' disease may require treating both the
thyroid gland as well as the eyes, and involves one of a number of modalities. Almost all
patients are started on anti-thyroid drugs: PTU (or Propylthiouracil), or Tapazole,
(Methimazole). These medications go to the thyroid gland and prevent it from taking up
iodine so that it prevents the thyroid from making thyroid hormone. There are small
differences between the two medications and there may be different indications for one or
the other in a given patient. (Also see our pamphlet "anti-thyroid medications")
Radioactive iodine is an especially useful agent for the
treatment of hyperthyroidism. Once radioactive iodine is taken up by the thyroid gland,
the radioactivity kills the thyroid gland and stops the hyperthyroidism. This sounds
drastic, but radioiodine has been a standard hyperthyroid treatment for more than 50
years. The resulting underactive thyroid gland can then easily be treated by thyroid
hormone replacement. There are instances in which radioactive iodine is not the agent of
first choice, such as in the very young or in women contemplating childbirth in the
immediate future, and pregnant women. Additionally, if a patient is doing well on a small
dose of PTU or Tapazole, there is little reason to use I131.
Surgery is another way of treating Graves' disease by
taking out some or most of the affected gland. This had previously been one of the more
popular ways of treating Graves' disease prior to the standardization of anti-thyroid
medications, radioactive iodine, as well as thyroid blood tests to follow-up patient's
progress. Because of the small but real risk of surgery in a patient who has
hyperthyroidism, however, and because of the sophistication of the other two methods of
treatment, surgery has definitely been relegated to a third place in the treatment of
Graves' disease.
Overall, however, almost all patients, regardless of the
ultimate or "definitive" treatment they receive, all begin by taking
anti-thyroid hormone medication. Many choose, after discussing it with their physician, to
remain on these medications as the treatment of choice.
HOW LONG DO I HAVE TO STAY ON MEDICATIONS FOR GRAVES'
DISEASE?
In approximately one out of every five, or 20% of
individuals treated with anti-thyroid medications, a spontaneous remission or a cessation
of the disease will occur within five years time. Unfortunately, half of these people, or
10% of the original group, will have a reoccurence or flare in their Graves' Disease,
requiring re-starting of treatment.
In the other 80% who never had a remission, should
anti-thyroid medication be the chosen method of treatment, treatment will probably need to
be extended for many years, possibly for a lifetime.
WHAT ABOUT SPECIAL TREATMENTS FOR THE EYES IN GRAVES'
DISEASE?
The treatment of the eye disease of hyperthyroidism
involves following the situation carefully and judging how severely the eyes are affected.
The more difficulties are encountered with the sandy, gritty, sensations that can occur,
redness of the eyeball, and visual changes, the more aggressive the treatment may have to
be. Eye drops, eye drops containing steroids, orally acting steroids, small dose radiation
therapy to the eyes, and even surgery to reduce the pressure on the eye sockets, all in
increasing order of aggressiveness and invasiveness have been used in treating the eye
disease of hyperthyroidism.
It should be said however, that only a very small
percentage of patients with Graves' disease eventually have any significant deterioration
in the eye disease of hyperthyroidism, (known as exophthalmos), and that most have a very
easy to treat and productive course usually by treating the hyperthyroidism itself.
It is important to adjust the type of therapy directed
against Graves' disease and/or the eye problem on regular basis depending on the route
chosen by the physician and the patient. This type of close follow-up helps to prevent any
sudden unexpected and deleterious changes in the course of the illness.
Naturally, should any drastic changes occur in anybody
with Graves' disease, notification of their physician at once, usually an endocrinologist
who is specialized in treating disorders of thyroid and the like, is mandatory.
