A Little Gland with a Big Job: Thyroid Disease

For a small gland, the thyroid packs a punch. This small butterfly-shaped gland found in the neck just below the Adam’s apple influences every organ, tissue, and cell in the body.

In short, it controls our metabolism. The thyroid produces the hormones T3 and T4, which tell our body how to use energy. The “thermostat” that tells the thyroid how much hormone to produce is located in the base of our skull and is called the pituitary gland. When our thyroid hormone levels decrease or increase, the pituitary gland releases its own hormone, TSH, which, in turn, tells the thyroid to produce more or less thyroid hormone.

More than 20 million Americans suffer from either an overactive or an underactive thyroid gland. As many as half the cases of thyroid disease in the United States go undiagnosed. If left untreated, a diseased thyroid can elevate your cholesterol levels and cause infertility, muscle weakness, osteoporosis, and, in rare cases, coma or death.

Hyperthyroidism occurs when the thyroid produces too much hormone and our metabolism goes into overdrive. Some of the symptoms may include irritability, tremors, muscle weakness, weight loss, sleep disturbances, and an enlarged thyroid.

One of the most common causes of hyperthyroidism is Grave’s disease, or diffuse toxic goiter, an enlargement of the thyroid usually due to an autoimmune condition though sometimes unexplained. There are other causes of hyperthyroidism, such as a nodule within the thyroid gland that begins to release large quantities of hormones.

Hypothyroidism is the opposite of hyperthyroidism. In this condition, the thyroid gland makes too little thyroid hormone, and our metabolism slows down. Symptoms include fatigue, weight gain, a hoarse voice, an intolerance to cold, and menstrual irregularities. One of the most common reasons for hypothyroidism is an inflammation of the thyroid, which is called thyroiditis.

This condition usually involves the immune system; antibodies are produced against the thyroid gland, which interfere with its normal function.

One of the key elements needed for a normal thyroid function is iodine. Too much or too little iodine can alter the hormone levels. Although this condition has been corrected in industrialized societies with the introduction of iodized salt, it is still very prevalent in many areas of the world.

The diagnosis of thyroid disease is relativity easy to make, usually by checking the levels of hormone such as TSH. If an enlarged thyroid gland is suspected, imaging tests such as ultrasound or MRI can confirm the diagnosis. If a tumor is suspected, a biopsy will be needed for confirmation; effective treatment is available, including surgery.

Hormone replacement therapy (HRT), usually a synthetic hormone called levothyroxine, is the key management tool for a hypoactive thyroid. In cases of hyperactive thyroid, reducing the amount of hormone regulates the thyroid gland. In such cases radioactive iodine, which disables the thyroid, is prescribed. Thyroid surgery is reserved for hyperactive areas of the thyroid, where a nodule is producing large quantities of hormone.

Though thyroid disease is a lifelong condition, when properly treated people can live healthy, normal lives. Both men and women should be screened for thyroid disease after the age of 35.

Click here to check out Dr. Manny's book The Check List (Harper Collins, 2007), from which this article was excerpted.

Dr. Manny Alvarez is the managing editor of health news at FOXNews.com, and is a regular medical contributor on the FOX News Channel. He is chairman of the Department of Obstetrics and Gynecology and Reproductive Science at Hackensack University Medical Center in New Jersey. Additionally, Alvarez is Adjunct Professor of Obstetrics and Gynecology at New York University School of Medicine in New York City.