THYROID

The thyroid is a small gland located below the skin and muscles at the front of the neck, just at the spot where a bow tie would rest. It's brownish red, with left and right halves (called lobes) that look like a butterfly's wings. It's light like a butterfly, too, and usually weighs less than an ounce.

As small as it is, though, the thyroid has an enormously important job to do, especially for teens. It manufactures the hormones that help control metabolism and growth. To do its job, the thyroid needs a chemical element called iodine that the body absorbs from the foods you eat and the water you drink. The entire body contains about 50 milligrams of iodine. About 1/5 to 1/3 of that supply (10 to 15 milligrams) is stored in your thyroid. The thyroid combines the iodine with tyrosine (an essential amino acid) to make important hormones.

Thyroid hormones are released from the gland and travel through the bloodstream to your body's cells. They help control the growth and the structure of bones, sexual development (puberty), and many other body functions. By helping your cells convert oxygen and calories into the energy they need to work properly, these hormones are important in determining if your body will mature as it should. Thyroid hormones also directly affect how most of your organs function. So if your thyroid isn't operating properly, you can have problems in lots of other parts of your body.

What Is Thyroid Disease?

Thyroid disease occurs when the thyroid gland doesn't supply the proper amount of hormones needed by the body. If the thyroid is overactive, it releases too much thyroid hormone into the bloodstream, resulting in hyperthyroidism. ("Hyper" is from the Greek, meaning "over" or "above.") Hyperthyroidism causes the body to use up energy more quickly than it should, and chemical activity (like metabolism) in the cells speeds up.

An underactive thyroid produces too little thyroid hormone, resulting in hypothyroidism. ("Hypo" means "under" or "below.") When the amount of hormone released into the bloodstream is below normal, the body uses up energy more slowly, and chemical activity (metabolism) in the cells slows down.

Although they are two different conditions, in both hypothyroidism and hyperthyroidism the thyroid can become larger than normal. An enlarged thyroid gland is a lump that can be felt under the skin at the front of the neck. When it is large enough to see easily, it's called a goiter. People who don't get enough iodine in their diets also can get an enlarged thyroid, but this is rare in the United States because foods here usually supply enough iodine.

Treatment of Thyroid Disorders Whatever your thyroid problem, chances are you take thyroid hormone to treat it. In hypothyroidism, thyroid hormone restores metabolism to normal. Most people with hyperthyroidism ultimately take thyroid hormone since the approach to treatment usually means shutting off the natural levels of hormone. Today's thyroid medicine of choice is levothyroxine sodium. This synthetic version of natural thyroid hormone costs only about 15 cents a day.

Hyperthyroidism

Hyperthyroidism can cause nervousness, irritability, increased perspiration, intolerance to heat, fatigue, difficulty sleeping, a fast heartbeat, irregular menstrual periods in girls, and muscle weakness. People with this problem might lose weight even though they're eating more than usual. The eyes may feel irritated or look like they're staring. Sometimes the tissues around the eyes become inflamed and swollen, and the eyes appear to bulge out, but this is less common in teens than in adults with hyperthyroidism

Hypothyroidism

A person with mild hypothyroidism may feel just fine - in fact, the condition might cause no symptoms at all. However, symptoms can become more obvious if hypothyroidism progresses.
People with underactive thyroids might feel depressed and sluggish. They might gain weight, even though they're not eating more or getting less exercise than usual. Teens with hypothyroidism also might have slow growth in height, slow sexual development, irregular menstrual periods in girls, muscle weakness, dry skin, hair loss, poor memory, and difficulty concentrating.

Hypothyroidism is usually easily diagnosed with a physical examination and blood tests, and treatment with thyroid hormone replacement pills can restore normal levels of thyroid hormone in the blood. This treatment is pretty simple, but it does require doctor visits once or twice a year for an examination, blood tests, and medication adjustments as needed.