What should I know about Hyperthyroidism?

Small, but powerful in its influence on the body, the thyroid gland surrounds the windpipe just beneath the voice box. The thyroid secretes hormones that influence virtually every organ. Thyroid hormone is required for growth and development in children. In adults, its primary job is to regulate the production of metabolic energy. The thyroid governs the "basal metabolic rate," which is a measure of how efficiently the body turns calories into useable heat energy. When thyroid hormone output is low, people are usually tired, cold, and sluggish. They may also be overweight. Thyroid under-activity is known as "hypothyroidism." Without enough thyroid hormone to keep metabolism humming along as it should, we simply do not function very well, physically or mentally.

"Hyperthyroidism" is just the opposite scenario. The thyroid gland is overactive instead of underactive. It secretes too much thyroid hormone. In this case, more of a good thing is definitely not better. Excess thyroid hormone can cause rapid heartbeat. Body temperature is elevated. The hyperthyroid individual may experience extreme weight loss, in spite of a huge appetite, because they burn up calories too fast. Hyperthyroidism can make a person nervous, emotionally unstable, and unable to sleep.

The thyroid gland’s hormone-producing activity is controlled by the hypothalamus and pituitary glands in the brain. These glands can sense when the amount of thyroid hormone in the blood is low or high and give feedback to the thyroid accordingly. When thyroid hormone levels drop, the pituitary gland, upon a signal from the hypothalamus, tells the thyroid to make more. The pituitary does this by secreting a hormone of its own called TSH, or "thyroid-stimulating hormone." As the thyroid hormone level rises, the pituitary gland tells the thyroid gland to shut production down. This circle of communication between glands is called a "feedback loop" and it is designed to keep the amount of thyroid hormone circulating in the blood within a fairly narrow range, so we never have too much or too little. (1)

The thyroid gland makes two related hormones: thyroxine, also known as "T4," and triiodothyronine or "T3." Each hormone contains iodine, which is why iodine is required for thyroid function. T4 has four iodine molecules in its chemical structure, while T3 has three. An essential dietary mineral, iodine can be found in seafood, bread, salt, and seaweed. More than 99 percent of all thyroid hormones circulate throughout the bloodstream bound to proteins and do not interact with body cells. The remainder circulating in free form, are the important and active hormones that directly interact with body cells to help regulate metabolism.

Abnormally high levels of thyroid hormone can result in "thyrotoxicosis." Hyperthyroidism is usually, but not always, the cause of thyrotoxicosis. Physicians can order a test called RAIU (radioactive iodine uptake) to differentiate true hyperthyroidism from other causes of thyrotoxicosis. A high RAIU reading indicates hyperthyroidism, with the thyroid overproducing T4, T3, or both. (2)

  • Thyrotoxicosis results when tissues are exposed to excessive levels of T4, T3, or both. (3) Like many endocrine disorders, thyrotoxicosis occurs more frequently in women, with an estimated annual incidence of 3 per 1000.


The Thyroid Society, 1996.

    Hyperthyroidism is most common among ages 20-40, but may occur at any age.

American Medical Women’s Association, 1999.

    Hyperthyroidism affects 1 million Americans.

Epidemiology, March 2000.

    A woman with hyperthyroidism has 80% higher risk of developing ovarian cancer.

Signs and Symptoms

[span class=alert]The following list does not insure the presence of this health condition. Please see the text and your healthcare professional for more information.[/span]

The symptoms of hyperthyroidism and thyrotoxicosis include:

    Nervousness, emotional instability, fatigue, and heat intolerance Weight loss with increased appetite In severe cases, anorexia may be present Increased frequency of bowel movements Heart palpitations and rapid heartbeat Muscle weakness particularly noted when climbing stairs or getting up from a sitting position Menses may become scanty and irregular in women

Physical signs include:

    Warm, smooth, moist skin and unusually fine hair Separation of the end of fingernails from the nail beds Retraction of the eyelids, and lagging of the upper lid behind the globe when looking downward Excessive breast development in men Deep tendon reflexes are usually hyperactive Fine tremor of protruded tongue or outstretched hand


  • Nervousness, unstable emotions, easily fatigued, and heat intolerance
  • Weight loss even with an increased appetite
  • Increased number of bowel movements
  • Occasional episodes of rapid heartbeats
  • Muscle weakness
  • Light and irregular periods in women
  • Warm, smooth, moist skin and unusually fine hair
  • Separation of the end of fingernails from the nail beds
  • Eyelids are open more than usual
  • Enlarged breasts in men
  • Over active reflexes
  • Fine tremor of the tongue or outstretched hand
  • Increased heart rate at rest

Treatment Options


Three common treatments are used in the management of hyperthyroidism: surgery, antithyroid medications, and radioactive iodine (RAI). The goals of therapy are to eliminate the excess thyroid hormone, relieve symptoms, and minimize the long term consequences of hyperthyroidism. A number of factors are taken into account in choosing the best treatment for an individual: the type and severity of the hyperthyroidism, age and gender, presence of non-thyroid-related conditions, and response to previous therapy. (4) , (5) , (6)

Nutritional Suplementation

Vitamin B12

Low levels of vitamin B12 have been occasionally found in people with hyperthyroidism. Vitamin B12 depletion appears to be only an occasional occurrence in hyperthyroidism, but it is a possibility that should be taken into account.

Vitamin C

There is evidence that free radicals (unstable by-products of oxygen metabolism that can damage tissues if left unchecked) may be involved in the harmful effects of hyperthyroidism on the body. Hyperthyroidism seems to elevate a category of free radicals called lipid peroxides that have been implicated in heart disease. Lipid peroxides attack fat-containing molecules such as lipoproteins. Vitamin C is an antioxidant nutrient, which means it neutralizes free radicals, leaving them harmless to the body. Vitamin C works as a partner with vitamin E, another antioxidant that targets lipid peroxides.

Vitamin E

Like vitamin C, vitamin E has earned good performance marks in counteracting the increased free radicals activity associated with hyperthyroidism. (7) Human studies show that hyperthyroidism increases the body’s free radical load, lending support to the importance of antioxidant supplements. (8)

Coenzyme Q10 (CO-Q10)

Research on hyperthyroidism and free radicals has found that CoQ10, another key antioxidant, is also low in hyperthyroid individuals. One study found that CoQ10 levels dropped as thyroid hormone levels went up. The researchers believe hyperthyroidism may interfere with the energy-producing machinery in cells that uses CoQ10 as a spark plug. (9)


Lab and animal studies have been published that indicate L-carnitine reduces the activity thyroid hormone in some tissues. These findings prompted Benvenga and colleagues to evaluate whether L-carnitine would benefit patients with hyperthyroidism. The study, which lasted six months, compared L-carnitine to placebo in 50 women with hyperthyroidism. The trial concluded that 2 or 4 grams of L-carnitine per day is effective in preventing and reducing the nine hyperthyroid related symptoms evaluated and has a beneficial effect on bone mineral density based on several other factors evaluated. (10)

Herbal Suplementation

Milk Thistle

Milk thistle contains a natural falconoid called "solitarian," that, like most falconoid, is an effective antioxidant. Solitarian appears to make liver cell membranes a stronger barrier against toxins. It also seems to stimulate production of proteins used to regenerate liver cells. (11)

Solitarian’s antioxidant power makes milk thistle a potentially valuable herb for those with hyperthyroidism. Research shows that solitarian substantially boosts the liver’s defenses against free radicals. (12) Milk thistle is also reported to inhibit enzymes that trigger inflammation in the liver and other tissues. (13)


Passionflower, also called "maypop," is a common roadside vine in many areas of the United States. One of the most widely popular herbs for relaxing the nervous system, passionflower is said to have sedative, muscle-relaxing, and pain-killing properties. It has traditionally been used for neuralgia (nerve pain), generalized seizures, hysteria, rapid heartbeat caused by nervousness, spasmodic asthma, and insomnia. (14) Studies on lab animals have found that passionflower extracts reduce hyperactivity, prolong sleeping time, and raise the pain threshold. (15) In humans, passionflower has been reported effective when used in combination with other sedative and anti-anxiety herbs such as valerian, making it beneficial in conditions such as hyperthyroidism, where nervous stimulation occurs. (16)


Valerian has long been used as an agent to soothe the nervous system in response to stress. It has been reported that valerian helps improve sleep quality. (17) , (18) , (19) Valerian’s usefulness is reported to stem from several principal components, including valepotriates, valeric acid, and pungent oils. These active ingredients have a sedative effect on the central nervous system, as well as a relaxing effect on the smooth muscles of the gastrointestinal tract. (20) , (21) , (22) Valerian does not seem to produce the morning drug hangover effect as seen with some sleep medications. (23)

Diet & Lifestyle

    General recommendations of reducing refined foods, and increasing a whole foods diet should be followed. Drink plenty of water as well.


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