Thyroid Guide Index
Types Of Thyroid Conditions
|What Is Thyroid Disease?
Any disorder which affects the ability of the thyroid to work efficiently is classified as thyroid disease. The thyroid is found on the front of the neck, just below the Adams apple. Its role is to produce two very important hormones called triiodothyronine (or T3 for short) and thyroxine (T4). These hormones circulate throughout the body and control our metabolism (the rate at which we burn calories and how fast the heart beats). If the thyroid does not produce enough hormones our system slows down and we gain weight and are prone to fatigue and constipation. If it produces too many hormones we feel hyper and suffer cardiac palpitations, mood swings and weight loss. Fluctuating levels of hormones can also affect the menstrual cycle, your hair, skin and nails as well as cause infertility and heart failure. Thyroid disease affects more than 200 million people worldwide, but it is 10 to 15 times more common in women than in men. The fact that women are more prone to developing thyroid problems, particularly at puberty, during pregnancy and menopause suggests there is some connection between the thyroid and ovarian function.
What Are The Main Types Of Thyroid Disease?
Hypothyroidism (low levels of thyroid hormones)
Hypothyroidism is the most common thyroid disorder, occurring in 10 percent of all women. Currently about 1.5 million Americans are diagnosed with the condition. As it can develop gradually, you may not first be aware of the symptoms. Signs include moderate weight gain (10 to 15 pounds), feeling cold more often, slow hair or nail growth and unusual tiredness. If untreated, hypothyroidism can eventually lead to a life-threatening coma. Almost half of all cases of the disorder are either due to a previous treatment for an overactive thyroid or due to Hashimoto's disease (an autoimmune disorder where the body attacks it's own thyroid tissue). In younger women the condition can lead to infertility. Treatment usually involves taking a hormone replacement pill for life.
Hyperthyroidism (over production of thyroid hormones)
Excessive hormones cause the person to become hyper, raising the body's metabolic rate. Symptoms of hyperthyroidism include moderate weight loss, rapid heartbeat, intolerance to heat, mood swings, and diarrhea and in many cases bulging eyes (image). It can also cause a goiter, an enlarged swelling at the end of the throat. The most common cause of hyperthyroidism is Graves disease, an autoimmune disease (see also causes of thyroid disease). Symptoms tend to start between the age of 30 and 60 but can occur at any age. In Europe doctors tend to treat patients with antithyroid drugs to suppress hormone production, but these can have unpleasant side effects and cannot be given to pregnant women. In America doctors tend to choose radioactive iodine as a hyperthyroidism treatment. Currently about 375,000 Americans are diagnosed with the condition.
Thyroid nodules are little bumps which appear on the thyroid. You may have one or several, they can be solid, or filled with fluid or blood. Most do not cause symptoms and do not need treatment. However, sometimes they can lead to hyperthyroidism or become big enough to cause problems with breathing or swallowing. It is possible to see a nodule yourself by looking in a mirror. Raise your chin slightly and look for a bump on either side of the windpipe below the Adams apple. If the lump moves up and down as you swallow it could be a nodule. Have it checked by your doctor because about 5 percent of incidences are cancerous.
A goiter (image) is an abnormally enlarged thyroid which is usually a symptom of one of the above mentioned conditions. If it becomes too large it can cause difficulties swallowing or breathing. Treatment depends on the cause - whether it is the result of too much or too little thyroid hormone production.
Thyroid cancer (image) is relatively rare (37,500 Americans have it, of which 2,250 die every year), and it comes in different forms. All thyroid cancers are slow developing and are generally symptom-free except for a painless lump on the base of the neck. If there are symptoms, it is likely to be difficulties swallowing and hoarseness.
What Are The Symptoms?
The symptoms of thyroid disease depend on the type of disease you have. Here is a list of signs of the main two types (quick image view):
||Frequent bowel movements
What Are The Risk Factors For Thyroid Disease?
Women are much more likely than men to develop all types of thyroid conditions. Although thyroid problems are more likely to occur after the age of 30, between 4 to 7 percent of women develop it in the months following childbirth (see thyroid disease and pregnancy). Thyroid conditions tend to run in families. You may also be at high risk if you have:
• Type 1 diabetes.
• Pernicious anemia (decrease in red blood cells).
• Prematurely gray hair.
• Vitiligo (a skin condition where patches of discoloration appear on the skin).
How Is It Diagnosed?
Doctors usually perform a physical examination and order some blood tests to diagnose thyroid disease. The FT4 and TSH blood tests are normally accurate enough to give a definitive answer (see thyroid tests). The FT4 (free thyroxine) test measures the levels of free hormones circulating in your body. If the levels are higher than normal it indicates hyperthyroidism and if they are low it suggests hypothyroidism. A TSH (thyroid-stimulating hormone) test is also carried out to test thyroid function. If your TSH levels are low you have hyperthyroidism, if it is high you have hypothyroidism.
Doctors used to perform a radioactive iodine uptake test to diagnose thyroid disease. This test needs to be carried out in a hospital with a nuclear medicine laboratory facility. The patient swallows a capsule of radioactive iodine and a device like a Geiger counter is passed over the thyroid to measure the radioactivity and uptake of iodine. If the thyroid is not functioning properly the iodine will settle in a particular pattern. This test is less common these days as the TSH and FT4 blood test are usually accurate enough.
People with thyroid nodules may be offered a thyroid scan, which also involves swallowing a radioactive iodine capsule. However, in this test, a scan is used to give an internal picture of the thyroid. It helps to determine if the nodules are cancerous, and also assists in the management of thyroid cancer. If the doctor suspects cancer, he may order a fine needle biopsy to take a sample of tissue from the thyroid for investigation.
How Is It Treated?
Different types of thyroid disorders need different types of treatment, ranging from nothing at all (some goiters and nodules) to medications and surgery.
Hypothyroidism: Is treated by a hormone supplement pill which needs to be taken for life. Occasionally some people are able to stop taking it after a few years if their blood tests come back normal.
Hyperthyroidism: Depending on the severity of the condition, there are 3 main treatments: antithyroid drugs, radioactive iodine to destroy part of the thyroid or surgery to remove part of the thyroid gland.
Thyroid Cancer: Surgery is often required to remove cancerous tissue, and is usually followed up with radioactive iodine.
Nodules: Treatment falls between the extremes of nothing at all, to radioactive iodine and surgery to remove nodules. It depends on how many bumps you have and if they are cancerous or not.
Should All Women Be Screened For Thyroid Problems?
As thyroid disease is such a common problem and the initial signs can be missed, it is recommended that all women over the age of 35 are tested every 5 years. Your doctor will need to take a blood sample to test your TSH levels. A normal healthy range is between 0.5 and 5. If your doctor tells you that your screening is normal, but you are showing symptoms of thyroid disease, ask him what your TSH level is. If it's above 2.5 ask him to give you a trial treatment of thyroid medications to see how you react. Many scientists now believe that anything above 2.5 indicates a problem. Alternatively ask him to also perform a FT4 blood test. Screening is particularly important for pregnant women and the elderly. If you have more questions on this or any other topic, don't forget to visit our womens health questions section.