Thyroid

The thyroid is a small, butterfly shaped gland in the front of your neck. It produces hormones that affect your body's metabolism (how your body converts oxygen and calories to energy). That means the thyroid affects many functions that keep us healthy. Problems result when the thyroid produces either too much or too little hormone. Too much is called hyperthyroidism, too little is called hypothyroidism. The thyroid can also develop growths (nodules) or cancer. Below you'll find information on all these conditions.

Hypothyroidism

Hypothyroidism is too little thyroid hormone. It affects some 5 million people according to Thyroid Society for Education and Research (TSER). One in 4,000 babies is born with hypothyroidism. If not treated, it results in mental and physical retardation. All newborns in the United States are supposed to be tested for the condition. (Read about "Newborn Screenings")

Causes of hypothyroidism include:

• Hashimoto's disease - the most common cause of hypothyroidism, according to Thyroid Foundation of America (TFA), is Hashimoto's disease. This is an autoimmune disease (Read about "The Immune System") in which the immune system attacks and destroys the thyroid gland. It is also called Hashimoto's thyroiditis. Thyroiditis is inflammation of the thyroid gland. There is some evidence that Hashimoto's disease can have a hereditary link. The National Women's Health Information Center (NWHIC) also says it is the most common thyroid disease in the U.S. The Turner Syndrome Society says this happens frequently to women with Turner syndrome. (Read about "Turner Syndrome")
• thyroiditis - in addition to Hashimoto's disease, other less common forms of thyroiditis (inflammation of the thyroid) can result in hypothyroidism
• surgery or other treatment such as radiation that damages or removes the thyroid (Read about "Radiation Therapy")
• lack of iodine in the diet that results in a goiter or a swelling of the gland
• the natural aging process
• viral or bacterial infections (Read about "Microorganisms")

Some of the signs and symptoms of hypothyroidism according to AAFP, TSER and TFA include:

• slow heart rate (Read about "The Heart & Cardiovascular System")
• feeling lethargic, tired all the time
• drowsiness, even after a good night's sleep (Read about "Sleep")
• poor memory (Read about "Dementia")
• feeling cold
• weight gain
• lack of concentration
• thinning hair
• constipation (Read about "Constipation")
• dry or coarse skin (Read about "Skin")
• heavy menstrual flow (Read about "Menstrual Disorders")
• muscle cramps (Read about cramps in "Feet, Ankles and Legs")
• infertility (Read about "Infertility")

Too little thyroid hormone can also impact a woman's menstrual cycle and a number of other things too, says TFA. For example, it can affect cholesterol levels (Read about "Cholesterol") which in turn can result in other health problems such as heart disease. (Read about "Coronary Heart Disease") In addition, the American Association of Clinical Endocrinologists (AACE) warns women approaching menopause (Read about "Menopause") that thyroid symptoms sometimes mirror symptoms of menopause. AACE says that women who think they are having perimenopausal or menopausal signs should raise the issue of thyroid disease with their doctor.

Once again, one sign is probably nothing to worry about according to TSER, but if you have concerns, it is important that you see your doctor.

Thyroid problems are often diagnosed with blood tests. (Read about "Laboratory Testing") Tests can be done to measure the amount of thyroid hormones, as well as the amount of hormone (TSH) produced by the pituitary gland to stimulate the thyroid. Tests can also check for the presence of antibodies. A test can also be done to measure how much iodine is taken up by the thyroid gland. Once the cause is figured out, treatment can be started. With hypothyroidism, the problem can sometimes go away on its own. If it's caused by an infection, treating the infection can solve the problem. Hormone medication can also be used to replace the thyroid hormone. That - combined with blood tests - can then keep the problem regulated.

Hyperthyroidism

Hyperthyroidism is when the body basically speeds up; too much thyroid hormone is being produced. This can happen for a number of reasons, including:

Graves' disease - The most common causes of hyperthyroidism, according to the American Academy of Family Physicians (AAFP), is a condition called Graves' disease. Graves' disease is a type of autoimmune disease that causes over-activity of the thyroid gland. An autoimmune disease occurs when the body's immune system becomes misdirected and attacks the body's own organs, cells, or tissues. (Read about "The Immune System") The National Women's Health Information Center (NWHIC) says Graves' disease affects 2 percent of all women at some time in their lives, most often between the ages of 20 and 40. It also is considered a genetic disease that runs in families. (Read about "Genetics") Graves' disease is associated with swelling of the tissue around the eyes and bulging of the eyes. Symptoms of this disease can occur slowly or very suddenly and are sometimes confused with other medical problems. Graves' disease can also produce no visible symptoms at all.

Thyroiditis - Hyperthyroidism can also be caused by some forms of thyroiditis, which is an inflammation of the thyroid gland. For example, a type of thyroiditis called subacute thyroiditis, which may be caused by a viral infection, can cause a temporary increase in the amount of hormone produced by the thyroid.

Pregnancy - Hyperthyroidism can also develop after pregnancy. (Read about "Healthy Pregnancy") Postpartum thyroiditis is basically a swelling of the thyroid that occurs in 5-7 percent of women who give birth, and can cause temporarily high levels of thyroid hormone.

Nodules - Some nodules or adenomas can secrete too much hormone, leading to hyperthyroidism. (See thyroid nodules below)

As with all thyroid diseases, hyperthyroidism is more common in women than men, according to the Thyroid Society for Education and Research (TSER). Too much thyroid hormone can affect a woman's menstrual cycle (Read about "Menstrual Disorders") and cause calcium (Read about "Calcium") loss from your bones resulting in osteoporosis (Read about "Osteoporosis"), according to the Thyroid Foundation of America (TFA).

Some of the signs and symptoms of hyperthyroidism according to AAFP, TSER and TFA include:

• fast heart rate
• elevated blood pressure (Read about "Hypertension: High Blood Pressure")
• nervousness or irritability
• sweating (Read about "Sweating")
• weak muscles (Read about Endocrine Myopathies in "Neuromuscular Diseases")
• hands shaking
• losing weight even though you are eating as much if not more
• hair loss
• skin and fingernail changes
• increased bowel movements
• goiter or a swelling of the neck
• in women, decreased and less frequent menstrual flow (Read about "Menstrual Disorders")
• in men, slight swelling of the breasts

Just one of these symptoms does not mean you have hyperthyroidism according to TSER, but two or more, or different ones at different times, are a sign you should see your doctor.

Thyroid problems are often diagnosed with blood tests. (Read about "Laboratory Testing") Tests can be done to measure the amount of thyroid hormones, as well as the amount of hormone (TSH) produced by the pituitary gland to stimulate the thyroid. Tests can also check for the presence of antibodies. A test can also be done to measure how much iodine is taken up by the thyroid gland. Once the cause is figured out, treatment can be started. For hyperthyroidism, there are multiple options. TFA says there are four main therapies for hyperthyroidism:

• Antithyroid drugs have been in use since the 1940's and are often successful.
• Radioactive iodine can be used to destroy some thyroid tissue. The reminder may still be overactive but because there is less tissue, less thyroid hormone is produced.
• Surgery can be used to remove all or part of the thyroid, with the same result as with radioactive iodine. If all of the thyroid is removed, thyroid medication may be required to replace the missing thyroid hormone.
• Beta-blocking drugs can be used to block part of the hormone's actions and relieve many symptoms.

It is interesting to note that many people who suffer from hyperthyroidism and are treated, later in life suffer from hypothyroidism as the body slows down with aging.

Thyroid Nodules

Thyroid nodules are fairly common. You may have a thyroid nodule and not even be able to feel it. Most are benign, meaning they are not cancerous. But even non-cancerous nodules can cause a problem, for example, if they grow large enough to press on your windpipe. A nodule can also produce too much hormone, resulting in hyperthyroidism.

You may be more at risk of developing nodules if you have or have had thyroiditis. People who as children received head or neck x-ray treatments for tonsillitis or other conditions (generally from the 1920s to 1960s) are more at risk, as are people who have been exposed to radiation for other reasons.

If you suspect a nodule, it is important to have it checked. Tests can include blood tests that measure thyroid hormones. (Read about "Laboratory Testing") Scanning tests such as ultrasound (Read about "Ultrasound Imaging") or a special thyroid scan can be used. You may also have a biopsy (Read about "Biopsy"), in which a needle is inserted into the nodule to remove a sample of cells.

Tests are important because swelling in the thyroid can be a sign of thyroid cancer. (Read about "Thyroid Cancer") Again, while most nodules are benign, the National Cancer Institute (NCI) calls thyroid cancer the most common cancer of the endocrine system (Read about "Endocrine System"), so it is essential that you see your doctor if you notice any swelling or suspicious signs. If the nodule is not cancerous, but still growing and/or causing problems, treatment options include surgery to remove the nodule, radioactive iodine which can cause the nodule to shrink, or thyroid hormone suppression therapy.

Thyroid cancer

Although most thyroid nodules are benign, the National Cancer Institute (NCI) calls thyroid cancer the most common cancer of the endocrine system, resulting in about 1 percent of all cancers. The good news is the treatment success rate for thyroid cancer is very high.

(Read about Thyroid Cancer)