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Hyperthyreosis (Hyperthyrodism)

Description of Hyperthyreosis:

Hyperthyreosis (hyperthyroidism) is characterized by an increase in the activity of the thyroid gland. Enlargement of the thyroid gland, secondary to inadequate levels of iodine in the diet is known as thyroid goiter. A common cause of goiter in the presence of hyperthyreosis is known as Grave’s disease. This disorder is one of the most common causes of hyperthyroidism and is thought to be caused by an autoimmune mechanism. The thyroid gland is responsible for regulating the body’s metabolism through the production of thyroid hormone. Thyroid hormone is produced in two forms, active (T4) and inactive (T3). The body can convert T3 to active T4 under certain conditions. Anatomically, the thyroid is a butterfly-shaped organ located in the neck (next to the “Adam’s apple”). An increase in thyroid hormone can occur secondarily to elevate functioning of the thyroid gland (goiter), or it may occur when there is increased activity of the pituitary gland, located at the base of the brain.

Hyperthyroidism means your thyroid makes too much thyroid hormone. Your thyroid is a gland in the front of your neck; it controls your metabolism, which is how your body turns food into energy. It also affects your heart, muscles, bones, and cholesterol.

Having too much thyroid hormone can make a lot of things in your body speed up. You may lose weight quickly, have a fast heartbeat, sweat a lot, or feel nervous and moody. Or you may have no symptoms at all. Your doctor may discover that you have hyperthyreosis while doing a test for another reason.

Hyperthyroidism is easily treated with treatment you can lead a healthy life. Without treatment, hyperthyroidism can lead to serious heart problems, bone problems, and a dangerous condition called thyroid storm.


Common symptoms and signs of hyperthyreosis:

  • 1. Palpitations.
  • 2. Heat intolerance.
  • 3. Nervousness.
  • 4. Insomnia.
  • 5. Breathlessness.
  • 6. Increased bowel movements.
  • 7. Light or absent menstrual periods.
  • 8. Fatigue.
  • 9. Fast heart rate.
  • 10. Trembling hands.
  • 11. Weight loss.
  • 12. Muscle weakness.
  • 13. Warm moist skin.
  • 14. Hair loss.
  • 15. Staring gaze.


There is no one treatment that is best for all patients with hyperthyroidism. Many factors will influence the doctor’s choice of treatment, including the patient’s age, the form of hyperthyreosis, the severity of the disease and other medical conditions which may be affecting the patient’s health.

Currently, there are three principal ways to treat hyperthyreosis: drug therapy, radioactive iodine therapy and surgery.

Drug therapy includes using two types of drugs to control the hyperthyreosis. Initially, the doctor will prescribe either methimazole (Tapazole) or propylthiouracil (PTU) pills which are antithyroid agents. These drugs block the amount of thyroid hormone in the blood and make it more difficult for iodine to get into the thyroid gland.

Although these drugs have blocked the amount of thyroid hormone in the blood, there are still high levels of circulating thyroid hormone in the blood. To combat this, the doctor may also prescribe beta-blocker drugs, such as propranolol (Inderal), to block the action of the circulating thyroid hormone.

Radioactive iodine therapy is an alternative if drug treatment fails. The patient is given a capsule or a drink of water containing radioactive iodine. After being swallowed, the “radioiodine” is rapidly absorbed by the overactive thyroid cells and over a period of several weeks, the radioactive iodine damages the cells.

The result is the thyroid shrinks in size, thyroid production falls and blood levels return to normal. The radioactivity disappears from the body within a few days. Hyperthyroidism can reoccur from several months to many years after this therapy.

Surgery is the preferred treatment for people with a large goiter who chronically relapse after drug therapy and for people who refuse or who are not candidates for the radioactive iodine therapy.

The surgery, called a thyroidectomy, involves the surgical removal of part of the thyroid gland. If only a single lump or nodule within the thyroid is producing too much hormone, the surgeon can take out just that small part of the gland. If the entire gland is overactive, which is more often the case, a total thyroidectomy is needed. Sometimes, the surgeon can leave a small portion of the thyroid intact – just enough to produce adequate amounts of thyroid hormone. Depending on how much of the gland is left after surgery, the patient may need subsequent thyroid replacement therapy.

Causes and Risk factors:

There are several causes of hyperthyreosis. Most often, the entire gland is overproducing thyroid hormone this is called Graves’ Disease less commonly, a single nodule is responsible for the excess hormone secretion. We call this a “hot” nodule.

The most common underlying cause of hyperthyroidism is Graves’ disease. This condition can be summarized by noting that an enlarged thyroid (enlarged thyroids are called goiters) is producing way too much thyroid hormone. [Remember that only a small percentage of goiters produce too much thyroid hormone, the majority of thyroid goiters actually become large because they are not producing enough thyroid hormone]. Graves’ disease is classified as an autoimmune disease, a condition caused by the patient’s own immune system turning against the patient’s own thyroid gland. The hyperthyreosis of Graves’ disease, therefore, is caused by antibodies that the patient’s immune system makes which attach to specific activating sites on thyroid gland which in turn cause the thyroid to make more hormone. There are actually three distinct parts of Graves’ disease: [1] overactivity of the thyroid gland (hyperthyreosis), [2] inflammation of the tissues around the eyes causing swelling, and [3] thickening of the skin over the lower legs (pretibial myxedema). Most patients with Graves’ disease, however, have no obvious eye involvement. Their eyes may feel irritated or they may look like they are staring. About one out of 20 people with Graves’ disease will suffer more severe eye problems, which can include bulging of the eyes, severe inflammation, double vision, or blurred vision. If these serious problems are not recognized and treated, they can permanently damage the eyes and even cause blindness. Thyroid and eye involvement in Graves’ disease generally run a parallel course, with eye problems resolving slowly after hyperthyroidism is controlled.

Hyperthyroidism can also occur in patients who take excessive doses of any of the available forms of thyroid hormone. This is a particular problem in patients who take forms of thyroid medication that contains T3, which is normally produced in relatively small amounts by the human thyroid gland. Other forms of hyperthyroidism are even rarer. It is important for your doctor to determine which form of hyperthyroidism you may have since the best treatment options will change depending on the underlying cause.


Your doctor will first perform a physical examination to check for any obvious symptoms of hyperthyroidism. In addition, your doctor may run other tests, including:


Blood Tests — Blood tests are performed that measure the levels of the thyroid hormones, T4 and T3, which must be high to make a diagnosis of hyperthyroidism. The level of thyroid stimulating hormone (TSH) also is measured. With hyperthyroidism TSH is low while T4 and T3 levels are high.

Iodine Uptake Scan — This test measures thyroid function by determining how much iodine is taken up by the thyroid gland. Patients are given a small dose of radioactive iodine that is taken on an empty stomach. The iodine is concentrated in the thyroid gland or excreted in the urine over the next few hours. The amount of iodine that goes into the thyroid gland is then measured.

Thyroid Scan — This test typically is performed at the same time as the iodine uptake test because it also requires that a patient take radioactive iodine, which then concentrates in the thyroid gland. Thyroid scans use the emissions of gamma rays from radioactive iodine to obtain a picture of the thyroid.

Medicine and medications:

1. Propylthiouracil (PTU) PTU, used for the treatment of hyperthyroidism, exerts its actions by decreasing thyroid hormone synthesis, and by blocking the conversion of thyroxine (T4) to triiodothyronine (T3). In patients with Graves’ Disease (GD), PTU likely also exerts a beneficial effect on the immune disturbance underlying the development of GD, as discontinuation of PTU after an appropriate treatment course (12-24 months for most patients) is frequently association with disease remission, which may be long lasting or permanent. Some patients experience a bit of nausea, or mild stomach upset and many patients find that PTU leaves a bitter aftertaste.

2. Methimazole works, as does PTU, to reduce the levels of thyroid hormone by decreasing thyroid hormone synthesis. In contrast to PTU, methimazole does not significantly inhibit T4 to T3 conversion. However, Methimazole is effective when administered either in divided doses or only once a day, which may have some advantage in terms of drug compliance. This issue has been carefully studied, with increased compliance noted in the groups of patients treated with once a day Methimazole dosing.

3. Medications such as propranolol (Inderal), metoprolol (Lopressor), and other related drugs are known as b blockers, as they act to block the action of b adrenergic receptors that mediate the actions of adrenaline and noradrenaline. During the hyperthyroid state, our sympathetic nervous system activity is increased, and many of the symptoms that develop overlap with symptoms experienced during states of anxiety. For example, tremor, rapid heart beats, anxiety, restlessness, retraction of the eye lids and increased sweating are all symptoms that may be improved following institution of b blocker treatment. Patients with moderate to severe hyperthyroidism may benefit from treatment with a b blocker for several weeks to months until their hyperthyroidism is better controlled with medications such as PTU or methimazole, or radioactive iodine. Rarely, patients with obstructive lung disease, asthma or congestive heart failure or cardiomyopathy may have an adverse reaction to b blockers leading to increased difficulty with breathing. Accordingly patients with these types of lung or heart conditions should inform their physician about these co-existing problems prior to consideration of b blocker therapy

4. Iodine: Although iodine is taken up by the thyroid and used to make thyroid hormone, it can paradoxically suppress release of thyroid hormones from the thyroid gland for several days. Hence, in some patients with severe hyperthyroidism, iodine may be administered to try and shut off thyroid hormone release after PTU or methimazole has been started. For more information, see Iodine. Some patients with severe hyperthyroidism may also be treated for a few days to weeks with oral cholecystographic agents that are normally used for visualization of the gall bladder. These drugs inhibit conversion of T4 to T3 and also contain iodine that transiently blocks thyroid hormone release.

DISCLAIMER: This information should not substitute for seeking responsible, professional medical care.

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