Everything You Wanted to Know About Your Thyroid

But were afraid to ask...

/ Author:  / Reviewed by: Joseph V. Madia, MD

With so much of the medical-news spotlight devoted to heart disease, cancer and mental health, who gives much thought to the thyroid, that little butterfly-shaped gland in the front of your neck?

Truth is, thyroids influence a score of bodily functions, including heart rate, muscle performance, metabolism, bone health and cholesterol levels, among others. When thyroids fail at their job -- which is to make hormones that control the way your body uses energy -- serious effects follow.

Thyroids that secrete too much hormone result in a condition known as hyperthyroidism. When the gland doesn't secrete enough hormone, hypothyroidism results. These are the most common disorders involving the thyroid, and while these conditions can cause discomfort, they can usually be controlled well with medication.

Sometimes thyroids become enlarged and result in the formation of a small, harmless goiter (enlarged gland).

Cancer can also develop in the gland.

In short, there are a number of ways in which malfunctioning thyroids can disrupt your life. Luckily, advancements in research are leading to better treatments and greater understanding of the thyroid.

And now, in honor of Thyroid Awareness Month, let's take a closer look at this powerful little gland...

Overactive Thyroid (Hyperthyroidism)

Hyperthyroidism, which is most common in women under age 40, causes overactivity in the body's organs, resulting in symptoms such as sweating, rapid pulse, weight loss and eye problems. This condition can lead to Graves' disease, an autoimmune disorder in which the body attacks the thyroid, causing it to secrete too much hormone. Graves' disease is characterized by problems in energy regulation, hormone control and cell maintenance throughout the body.

Researchers at the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) have identified a chemical compound in Graves' disease that may prevent thyroid cells to reverting to their normal function. The finding could lead to an alternative treatment to the standard, more invasive therapies for the condition, including surgery, radioactive iodine and antithyroid drugs.

Underactive Thyroid (Hypothyroidism)

When thyroids don't pump out enough of the hormone we need to keep our bodies functioning, a drop in hormone levels caused by hypothyroidism can cause fatigue, depression and eventually lead to elevated cholesterol that contributes to heart-attack and stroke risk.

A number of factors can increase your risk of hypothyroidism, which usually occurs in older females. These include: surgical removal of the thyroid to treat hyperthyroidism; an autoimmune disorder known as Hashimoto's thyroiditis, in which a bodily attack of the thyroid results in less hormone output; exposure to excessive amounts of iodine; and certain drugs such as lithium.

An estimated 25 million suffer from hypothyroidism, but half of them are unaware of the condition.

Researchers from Johannes Gutenberg University in Mainz, Germany, have possibly found why hypothyroidism is linked to mood swings, depression and other mental health symptoms by examining cerebral images of 10 patients using positron emission tomography (PET) imaging. They discovered underactive thyroid correlated to decreased metabolism in the thalamus, the part of the brain that helps process information from the senses and transmit it to other parts of the brain.

The finding could yield more effective treatments for declines in mental functioning accompanying hypothyroidism.

Thyroid Cancer

Thyroid cancer presents a potentially life-threatening prognosis, although rare (the disease occurs in less than 10 percent of thyroid nodules.)

Symptoms of thyroid cancer include a lump or swelling in the neck (most common) as well as breathing and swallowing difficulties, wheezing, pain in the neck and sometimes in the ears, and frequent cough not related to cold.

Once treatment is completed, thyroid cancer rarely returns. The cancer also generally responds well to treatment.

A new drug known as Pazopanib, which halts blood-vessel growth in tumors, has been shown to be effective in a large number of patients with advanced differentiated thyroid cancers.

Review Date: 
January 15, 2011