Take a proactive approach to hypothyroidism. Engage in constant, open dialogue with your physician. Arm yourself with as much medical data as you can. And contact the resources listed in the links below to learn more. We've assembled some information that may be of interest to you, to help you get started.

Hypothyroidism is a condition in which your body lacks adequate thyroid hormone. If you have been diagnosed by your physician as having hypothyroidism, you are one of over five million Americans having this common medical condition. Some degree of thyroid hormone deficiency may affect as many as ten percent of all women. The most common causes of hypothyroidism are thyroid gland inflammation and previous treatment for an overactive thyroid gland.

Hypothyroidism may cause the thyroid gland, located at the base of the neck, to become inflamed and enlarged. Although the enlarged gland may not be noticeable when looking at the neck, the first sign of a swollen thyroid (also called a goiter) may be a "tight collar."

Left untreated, hypothyroidism and its symptoms usually worsen. Rarely, complications can result in severe life-threatening depression, heart failure or coma. Hypothyroidism can be easily diagnosed with a blood test and is treatable.

The number and severity of symptoms vary with the duration and degree of thyroid hormone deficiency. Almost any one symptom can be the main problem in one patient, and yet be of minor importance or missing in another. In fact, some individuals with hypothyroidism have no symptoms at all.

People with hypothyroidism may experience these symptoms:

• Fatigue
• Weakness
• Weight gain or increased difficulty losing weight
• Intolerance to cold
• Muscle aches and cramps
• Constipation
• Depression
• Memory loss
• Abnormal menstrual cycles

Others may notice:

• Facial and hand puffiness
• Slow movements
• Irritability
• Decreased libido
• Coarse, dry hair
• Dry, rough pale skin
• Hair loss

The thyroid gland is a butterfly-shaped gland located in the neck, in front of the windpipe. Its job is to produce the thyroid hormone levothyroxine (T4) which is then converted to triiodothyronine (T3) in other body tissues. These two thyroid hormones, T4 and T3, travel in the blood to every part of the body, where they influence metabolism. Among other things, metabolism refers to the way we burn calories, fat and sugar, and build muscles. The thyroid hormones also affect many body organs in specific ways—increasing the heart rate, for example.

Normally, the pituitary gland makes sure that the normal thyroid gland makes just the right amount of thyroid hormone. The pituitary constantly monitors the thyroid hormone level in blood and produces a hormone of its own, called thyroid stimulating hormone (TSH), which travels in blood to the thyroid and stimulates it to make thyroid hormones. If the thyroid gland is inflamed or otherwise injured, it may be unable to produce enough thyroid hormone to meet the body's needs.

The most common cause of thyroid gland failure is called autoimmune thyroiditis (or Hashimoto's disease), a form of thyroid inflammation caused by the patient's own immune system. Ordinarily, our immune system fights only outside invaders, like bacteria, and rarely attacks our own tissue. In autoimmune thyroiditis, however, the immune system damages the patient's own thyroid gland.

Another common cause of thyroid gland failure is previous treatment for an overactive thyroid gland, a condition called hyperthyroidism. When radioactive iodine or thyroid surgery has been used to control this condition, the thyroid often becomes underactive, sometimes years later. There are several other rare causes of an underactive thyroid gland, including diseases that make the pituitary gland unable to make enough TSH.

To be sure that a person's symptoms are really due to hypothyroidism and may be helped by levothyroxine treatment, it is very important that blood tests be done to confirm the diagnosis. Accurate and reliable laboratory tests can measure blood levels of T4and TSH. In the typical person with an underactive thyroid gland, the blood level of T4 will be low, while the TSH level will be high. Your physician will review the results of the tests and the clinical exam, and prescribe a treatment plan. After six to eight weeks of treatment, the same tests can be performed and the results used to judge whether a hypothyroid person's dose of levothyroxine medication is suitable, neither too little nor too much.

Sometimes blood samples are also checked to see if there are antibodies against the thyroid, a sign of autoimmune thyroiditis. Once treatment for hypothyroidism has started, it probably will continue for the patient's life. Therefore, it is of great importance that the diagnosis be firmly established.

The most satisfactory treatment is the oral administration of levothyroxine once daily, preferably in the morning. This medication, pure synthetic T4, replaces the T4that the thyroid gland fails to secrete. It comes in multiple strengths, which means that an appropriate dosage can be found for each patient. The dosage should be re-evaluated and possibly adjusted monthly until the proper level is established. The dose should then be re-evaluated annually. Ask your physician when you should make an appointment to review your dosage.

Patients may notice a slight response to therapy within 1 to 2 weeks, but the full metabolic response to thyroid hormone therapy is often delayed. It may take several weeks after restoration of normal serum thyroid hormone levels for the patient to feel completely normal. It is very important that a patient receive the correct amount of thyroid hormone. Not enough hormone may be indicated by continued fatigue, mental dullness or muscle cramps. Excessive thyroid hormone could cause symptoms of nervousness, palpitations or insomnia.

Research suggests that too much thyroid hormone may cause excessive calcium loss from bone. This would increase the patient's risk for osteoporosis, a bone thinning disease that can lead to fractures of the hip and vertebrae. For patients with heart diseases, an optimal thyroid dose is particularly important. Even a slight excess may increase the patient's risk for a heart attack or worsen angina. Physicians may feel that more frequent dose checks are appropriate. If you develop any new medical problems while you are using the prescribed medication, check with your physician.

T4 can be safely taken with most other medications. You should check with your healthcare professional before taking other medications. Women taking T4 who become pregnant should feel confident that the medication is exactly what their own thyroid gland would otherwise make. However, they should check with their physician since the T4dose may have to be adjusted during pregnancy.

Generally, when starting levothyroxine therapy, the physician will periodically repeat thyroid function test to evaluate how a patient is responding to therapy and whether a dosage adjustment is needed.

Thyroid hormone and TSH levels should be checked by your physician at least once a year to assure that the optimum dose of thyroid is being administered.

Most thyroid conditions are more common in women-often, women of childbearing age. It is important for them to learn the symptoms of thyroid disease and how it can affect fertility and pregnancy.

Infertility and Thyroid Disease

Both hypothyroidism and hyperthyroidism (overactive thyroid gland) can affect menstrual cycles and fertility. Hypothyroidism can cause irregular, heavy or absent menstrual periods. If severe, it can reduce fertility. Hyperthyroidism can cause irregular, lighter or absent menstrual periods. It, too, can reduce fertility, and it can lead to miscarriage.

If you are having trouble becoming pregnant or have had miscarriages, your doctor may order blood tests to check thyroid gland function. Fortunately, an underactive thyroid gland can be treated easily and safely with levothyroxine, both before and during pregnancy. However, if thyroid test results are normal, levothyroxine will not be helpful in treating infertility.

PREGNANCY AND THYROID DISEASE

Pregnancy and Hypothyroidism

Hypothyroidism is the most common thyroid disorder during pregnancy; it is often caused by an immune disorder called Hashimoto’s thyroiditis. Hypothyroidism can begin during pregnancy or within months after delivery. It may be hard to detect during pregnancy, because some symptoms of underactive thyroid, such as tiredness and weight gain, are common among pregnant women. Blood tests, particularly TSH tests, can determine whether hypothyroidism is causing such symptoms.

Fortunately, if underactive thyroid is detected and promptly treated during pregnancy, the baby should not be affected. Pregnant women can feel confident that they can safely take thyroid hormone medications, because these medicines—particularly levothyroxine—are essentially identical to the hormones made naturally by the thyroid gland. Neither mother nor baby will experience side effects if the dose is correct.

Pregnant women with previously treated hypothyroidism may need to increase their dose of thyroid medication. Every two to three months during the pregnancy, their TSH levels should be tested to determine the need for dose adjustment. After delivery, mothers can return to their pre-pregnancy dose, and two months later, their thyroid function should be retested.

It is important to note that prenatal vitamins contain iron, which can impair the absorption of thyroid hormone. Therefore, levothyroxine and prenatal vitamins should be taken at least four hours apart.

Pregnancy and Hyperthyroidism

The most common cause of hyperthyroidism during pregnancy is Graves’ disease. As with hypothyroidism, hyperthyroidism may be overlooked in pregnant women. They may mistake rapid heartbeat, nervousness, trouble sleeping, nausea, weight loss and feeling warm with symptoms of pregnancy. An accurate diagnosis is based on history, physical exam and laboratory testing.

Hyperthyroidism in pregnant women can lead to miscarriage, early labor, stillbirth and birth defects, as well as severe hyperthyroidism in the mother. Therefore, treatment is vital. Experts consider propylthiouracil (PTU) the safest medication for pregnant women with overactive thyroid. PTU can affect the fetus’s thyroid gland, so the mother must be monitored closely with examinations and monthly blood tests. In patients who cannot take the medication (for example due to serious side effects), her thyroid gland must be removed.

Pregnant women should never take radioactive iodine (often given to nonpregnant patients with overactive thyroid), because it can damage the baby’s thyroid gland.

Until their hyperthyroidism is under control, pregnant women can temporarily take medications called beta-blockers to help treat rapid heartbeat and tremor caused by hyperthyroidism. Beta-blockers should be used sparingly, because they may affect the development of the fetus.

Treating hyperthyroidism during pregnancy can be tricky, so women who plan to have children should have this thyroid condition permanently cured before conceiving. Radioactive iodine is usually the recommended cure.

Postpartum Thyroiditis

One in twenty women develops thyroid inflammation within a few months after delivering her baby. This condition, called postpartum thyroiditis, is painless and causes little or no enlargement of the thyroid gland. However, the condition interferes with the gland’s even production of thyroid hormones. As a result, large amounts of thyroid hormone may leak out of the inflamed gland and cause hyperthyroidism, which can last for several weeks. Later on, the injured gland may not be able to make enough thyroid hormone, which can result in temporary hypothyroidism.

New mothers often do not realize they are experiencing hyperthyroidism or hypothyroidism; they typically blame the symptoms on lack of sleep, nervousness or depression.

Fortunately, postpartum thyroiditis disappears on its own after one to four months. Until then, some women choose to alleviate symptoms by taking beta-blockers. If temporary thyroid deficiency later develops, it can be treated for one to six months with levothyroxine.

If you’ve experienced thyroiditis before, you are likely to experience it again after future pregnancies. Although it usually resolves on its own, one out of four women with the condition develops a permanently underactive thyroid gland. This thyroid deficiency can be treated safely with levothyroxine.