Hyperthyroidism is the overproduction of thyroid hormones by an overactive thyroid gland.
Located in the front of the neck, the thyroid gland produces the hormones thyroxine (T4) and triiodothyronine (T3) that regulate the body’s metabolic rate by helping to form protein ribonucleic acid (RNA) and increasing oxygen absorption in every cell. In turn, the production of these hormones is controlled by a thyroid-stimulating hormone (TSH) that is produced by the pituitary gland.
When production of the thyroid hormones increases despite the level of TSH being produced, hyperthyroidism occurs. The excessive amount of thyroid hormones in the blood increases the body’s metabolism, creating both mental and physical symptoms.
The term hyperthyroidism covers any disease that results in an overabundance of thyroid hormone. Other names for hyperthyroidism, or specific diseases within the category, include Graves’ disease, diffuse toxic goiter, Basedow’s disease, Parry’s disease, and thyrotoxicosis.
Hyperthyroidism affects 2.5 million people in the United States, but could affect up to 4.5 million people because more than half of the people with thyroid disease don’t know they have it. Although it occurs at all ages, hyperthyroidism is most likely to occur after the age of 15.
There is a form of hyperthyroidism called neonatal Graves’ disease, which occurs in infants born of mothers with Graves’ disease. Occult hyperthyroidism may occur in patients over age 65 and is characterized by a distinct lack of typical symptoms. Diffuse toxic goiter occurs in as many as 80% of patients with hyperthyroidism.
Causes and symptoms
Hyperthyroidism is often associated with the body’s production of auto-antibodies in the blood that cause the thyroid to grow and secrete excess thyroid hormone. This condition, as well as other forms of hyperthyroidism, may be inherited.
Regardless of the cause, hyperthyroidism produces the same symptoms, including weight loss with increased appetite, shortness of breath and fatigue, intolerance to heat, heart palpitations (strong, very fast heartbeats), increased frequency of bowel movements, weak muscles, tremors, anxiety, and difficulty sleeping. Women also may notice decreased menstrual flow and irregular menstrual cycles.
Patients with Graves’ disease often have a goiter (visible enlargement of the thyroid gland), although as many as ten percent do not. These patients also may have bulging eyes. Thyroid storm, a serious form of hyperthyroidism, may show up as sudden and acute symptoms, some of which mimic typical hyperthyroidism but with the addition of fever, substantial weakness, extreme restlessness, confusion, emotional swings or psychosis, and perhaps even coma.
Physicians will look for physical signs and symptoms indicated by patient history. On inspection, the physician may note symptoms such as a goiter or eye-bulging. Other symptoms or family history may be clues to a diagnosis of hyperthyroidism.
An elevated basal (lowest range of normal) body temperature above 98.6 degrees Fahrenheit (37 degrees centigrade) may be an indication of a heightened basal metabolic rate (which measures the energy used to maintain vitality) and hyperthyroidism. A simple blood test can be performed to determine the amount of thyroid hormone in the patient’s blood.
The diagnosis usually is straightforward with this combination of clinical history, physical examination, and routine blood hormone tests. Radioimmunoassay, or a test to show concentrations of thyroid hormones with the use of a radioisotope (a chemical element capable of radioactive or atomic transformations) mixed with fluid samples, helps confirm the diagnosis.
A thyroid scan is a nuclear medicine procedure involving injection of a radioisotope dye that will tag the thyroid and help produce a clear image of inflammation or involvement of the entire thyroid.
Other tests can determine thyroid function and thyroidstimulating hormone levels. Ultrasonography (a test whereby high-frequency sound waves (ultrasound) are bounced off tissues and echoes are converted to pictures (sonograms), computed tomography or (CT) scan (an x-ray computer procedure that produces a detailed picture of a crosssection of the body), and magnetic resonance imaging (MRI) (an x-ray technique that produces a detailed image of the inner body using a powerful magnet, radio waves, and a computer) may provide visual confirmation of a diagnosis or help to determine the extent of involvement.
Alternative treatments for hyperthyroidism include nutritional therapy, herbal therapy, and homeopathy, the use of tiny doses of diluted and harmless remedies to catalyze healing.
Consumption of such foods as broccoli, Brussels sprouts, cabbage, cauliflower, kale, rutabagas, spinach, turnips, peaches, and pears can help naturally suppress thyroid hormone production. Dairy products and any stimulants such as tea, coffee, soda, and other caffeinated drinks should be avoided. Under the supervision of a trained physician, high dosages of certain vitamin/mineral combinations can help alleviate hyperthyroidism.
An experienced homeopath may give patients specific remedies tailored to their overall personality profile as well as their specific symptoms. Symptomatic treatments may include Iodium or Natrum muriaticum.
Other alternative treatments that may help relieve hyperthyroidism symptoms include traditional Chinese medicine and Western herbal medicine. Stress reduction techniques such as meditation also may prove beneficial. Patients should contact experienced herbalists for specific preparations and treatment.
Allopathy is the theory or system of medical practice that combats disease by use of remedies that produce effects different from those produced by the disease. Treatment will depend on the specific disease and individual circumstances such as age, severity of disease, and other conditions affecting a patient’s health.
Antithyroid drugs often are administered to help the patient’s body cease overproduction of thyroid hormones. In 2004, some drugs used to interfere with the thyroid gland’s uptake of iodine were propylthiouracil (PTU) and methimazole (Tapazole®).
Medication may work for young adults, pregnant women, and others. Women who are pregnant should be treated with the lowest dose required to maintain thyroid function in order to minimize the risk of hypothyroidism (underactive thyroid gland function) in the infant.
Radioactive iodine often is prescribed to damage cells that make thyroid hormone. The cells need iodine to make the hormone, so they will absorb any iodine found in the body. The patient may take an iodine capsule daily for several weeks, resulting in the eventual shrinkage of the thyroid, reduced hormone production, and a return to normal blood levels.
A single large oral dose of radioactive iodine simplifies treatment but should only be given to patients who are not of reproductive age or are not planning to have children, since a large amount can concentrate in the reproductive organs (gonads).
Patients treated with thyroidectomy, or surgery involving of partial or total removal of the thyroid, most often suffer from large goiter and have suffered relapses, even after repeated attempts to address the disease through drug therapy with iodine.
Following thyroidectomy or iodine therapy, patients must be carefully monitored for years to watch for signs of hypothyroidism, or insufficient production of thyroid hormones. Hypothyroidism can occur as a complication of thyroid production suppression.
Hyperthyroidism generally is treatable and carries a good prognosis. Most patients lead normal lives with proper treatment. The majority of patients who receive radioactive iodine report feeling better within about three to six weeks of treatment. Thyroid storm, however, can be life-threatening and can lead to heart, liver, or kidney failure. Some patients who undergo radioactive iodine treatment or surgery become hypothyroid.
There are no known prevention methods for hyperthyroidism, since its causes are either inherited or not completely understood. The best prevention tactic is knowledge of family history and close attention to symptoms and signs of the disease. Careful attention to prescribed therapy can prevent complications of the disease.