Thyroid Disorders
Overview
The thyroid is a small butterfly-shaped gland inside the neck, located in front of the trachea (windpipe) and below the larynx (voice box). It uses small amounts of iodine to produce two thyroid hormones - triiodothyronine (T3) and thyroxine (T4) - that travel though the blood to all tissues of the body.
Thyroid hormones control many aspects of health, including:
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The body’s "metabolic rate"
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body weight and temperature
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heart rate and blood pressure
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mental alertness
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growth in children
Another gland, called the pituitary gland, actually controls how well the thyroid works. The pituitary gland is located at the base of the brain and produces thyroid-stimulating hormone (TSH). The bloodstream carries TSH to the thyroid gland, where it tells the thyroid to produce more thyroid hormones, as needed.
The thyroid gland can become either overactive (hyperthyroidism) or underactive (hypothyroid) or develop nodules within it.
Other thyroid problems include cancer, thyroiditis (swelling of the thyroid gland), or a goiter, which is an enlargement of the thyroid gland.
Hyperthyroidism - Causes, Signs and Symptoms
Too much thyroid hormone from an overactive thyroid gland is called hyperthyroidism, because it speeds up the body's metabolism. One of the most common forms of hyperthyroidism is known as Graves' disease, after Robert Graves who first described it. This autoimmune disorder tends to run in families, although the exact nature of the genetic abnormality is unknown.
Because the thyroid gland is producing too much hormone in hyperthyroidism, the body develops an increased metabolic state, with many body systems developing abnormal function.
Symptoms
Hyperthyroidism more commonly affects women between the ages of 20 and 40, but men can also develop this condition. The symptoms of this thyroid condition can be frightening and include:
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Muscle weakness
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Fine tremor of the hands
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Fast heartbeat
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Fatigue
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Weight loss
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Diarrhea or frequent bowel movements
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Irritability and anxiety
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Vision problems (irritated eyes or difficulty seeing)
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Menstrual irregularities
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Intolerance to heat and increased sweating
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Infertility
What are Causes of Hyperthyroid?
Graves' disease
is the most common cause of hyperthyroidism. It occurs when the immune system produces antibodies that attack the thyroid gland, making it produce too much thyroid hormone and creating a hormone imbalance. This condition happens often in people with a family history of thyroid disease. In some patients with Graves' disease, one of the noticeable symptoms may be swelling behind the eyes, causing discomfort or increased tears or causing the eyes to push forward or bulge.
Other causes of hyperthyroidism include the following:
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Thyroid nodules. (Read more on THYROID NODULES)
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Taking too much thyroid hormone medication to treat other conditions.
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Subacute thyroiditis. This painful inflammation of the thyroid is usually caused by a virus. When the infection leaves, the condition improves.
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Lymphocytic thyroiditis and postpartum thyroiditis. These related autoimmune disorders cause a temporary painless inflammation of the gland. Thyroiditis is marked by lymphocytes (white blood cells) inside the thyroid and leads to leakage of thyroid hormone from the inflamed gland, raising hormone levels in the bloodstream.
Hyperthyroid Treatments
Antithyroid Drugs: These drugs work to decrease the amount of hormone the thyroid gland makes. For most patients, the preferred drug is methimazole (MMI) because of its safety record. Propylthiouracil (PTU) may be preferred for patients who are allergic to or intolerant of methimazole (MMI) and for pregnant women in their first trimester of pregnancy.
Antithyroid drugs usually have to be taken for an extended period of one to two years or longer. In approximately 50-60% of patients with Graves’ disease the thyroid condition may go away after a course of treatment, but there could be a relapse, even years later.
Beta-blockers: Beta-blocker drugs, such as propranolol, do not block the production of thyroid hormone. Instead, they control many troubling symptoms of this hormone imbalance, especially rapid heart rate, trembling, anxiety, and the high amount of heat the body produces with this condition.
Radioactive iodine: The thyroid gland normally collects iodine out of the bloodstream to make thyroid hormone. Radioactive iodine treatment involves taking a radioactive form of iodine that causes the permanent destruction of the thyroid. The response to treatment can take from 6 to 18 weeks. Because the radioiodine often destroys some of the normal function of the thyroid gland, people who have this therapy often need to take thyroid hormone for the rest of their lives to replace their hormone levels. Most physicians agree that the desirable goal of radioactive therapy is to completely remove thyroid gland function since then there is a very low chance of hyperthyroidism coming back.
Surgery: Removal of the thyroid gland (thyroidectomy) is another permanent solution but is often the least preferred option. This procedure must be performed by a highly skilled and experienced thyroid surgeon because of the risk of damage to nerves around the larynx (voice box) and to the nearby parathyroid glands, which control calcium metabolism in the body. Surgery is recommended when there is a large goiter (enlarged thyroid gland) that makes breathing difficult or when antithyroid drugs are not working, or when there are reasons not to take radioactive iodine. It may also be used in patients who also have thyroid nodules, especially when the nodules may be cancerous. In the latter instance, additional thyroid cancer treatment is often required.
After both radioactive iodine and surgery treatments, the patient will need to be monitored regularly for adequate thyroid hormone levels in the blood. After such treatment, most patients become hypothyroid and no longer produce enough thyroid hormone. For this reason, they must take a daily supplement of synthetic thyroid hormone to correct the hormone imbalance.
If left untreated, hyperthyroidism can lead to other health problems including congestive heart failure, irregular heart rhythm which predisposes to strokes as well as osteoporosis, which causes brittle bones.
Hypothyroidism
Too little thyroid hormone from an under-active thyroid gland is called hypothyroidism. In hypothyroidism, the body's metabolism is slowed. Several causes for this condition exist, most of which affect the thyroid gland directly, impairing its ability to make enough hormone. More rarely, there may be deficiency of the pituitary TSH, sometimes as a result of a pituitary gland tumor, which blocks the pituitary from producing TSH. As a consequence, the thyroid fails to produce a sufficient supply of hormones needed for good health. Whether the problem is caused by the thyroid conditions or the pituitary gland, the result is that the thyroid is underproducing hormones, causing many physical and mental processes to become sluggish.
Hypothyroidism can be a dangerous condition if untreated.
Symptoms include the following:
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Fatigue
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Mental depression
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Poor memory
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Sluggishness
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Feeling cold
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Weight gain
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Dry skin and hair and hair loss
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Constipation
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Menstrual irregularities
The most severe expression of hypothyroidism may be referred to as myxedema. If you have severe hypothyroidism, a significant injury, infection, or exposure to cold or certain medications may trigger a life-threatening condition called myxedema coma. This condition may cause a patient to lose consciousness and to develop hypothermia, a life-threatening low body temperature.
What are causes of hypothyroid?
Hashimoto’s Disease
is the most common cause of hypothyroidism in the United States. It occurs when the immune system produces antibodies that attack the thyroid gland, creating chronic inflammation that damages the gland and interferes with its ability to make enough thyroid hormone. It occurs more often in women than men and tends to run in families.
Hypothyroidism can be caused by several other conditions, including:
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Subacute, lymphocytic, or postpartum thyroiditis. These inflammations of the thyroid gland often start as hyperthyroidism, as stored thyroid hormone leaks out of the gland and raises hormone levels in the blood. Most people then develop temporary or, very rarely, permanent hypothyroidism.
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Drugs that affect thyroid function, such as amiodarone, which is used to treat heart rhythm abnormalities.
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A pituitary gland that does not make enough thyroid-stimulating hormone (TSH).
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Treatment for hyperthyroidism (too much thyroid hormone) with radioactive iodine or surgery.
Routine testing of babies at birth identifies any with congenital hypothyroidism, a condition in which the thyroid gland has not developed properly. This testing is essential for all newborns, because if hypothyroidism in not treated, a child could experience mental slowness or retardation, or fail to grow normally. Hypothyroidism during pregnancy can also negatively affect the baby, although if you are adequately treated and under regular supervision by an experienced endocrinologist there is no adverse effect on the baby’s development.
Hypothyroidism is increasingly common as we age. Women over 50 should consider being screened for thyroid deficiency every few years. Hypothyroidism affects as many as 15 percent of women over 70 years of age.
Hypothyroid Treatments
Hypothyroidism is treated by replacing the thyroid hormone the body needs. This is usually done with an oral tablet or pill of the thyroid hormone thyroxine (T4 or levothyroxine). A person will usually notice an improvement in his or her health and decreased symptoms of thyroid disease within two weeks. Severe cases of hypothyroidism, however, may take longer to correct and there is often a lag period between restoration of normal blood levels and full recovery from all the symptoms. Most patients with hypothyroidism will need to be on T4 treatment for the rest of their lives. They have to work closely with their doctor, take their medication as directed, and be monitored regularly in case the medication dose needs to be adjusted. If patients take too much T4, they can develop a mild case of hyperthyroidism. If they do not get enough, the symptoms of hypothyroidism will return.
A patient may need special attention if in addition to suffering from thyroid problems, he or she is:
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Older or has a weak heart. Thyroid hormone can make the heart work harder. A lower dose may be needed.
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Pregnant. Higher doses are usually needed during pregnancy. Frequent monitoring is required during this time, too, because the thyroid hormone dosage may change. An adjustment in dosage may be necessary after delivering the baby as well.
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Having surgery. A person should have enough T4 in his or her system before surgery to undergo the anesthesia and have a satisfactory recovery. If an individual is unable to take medicine by mouth, T4 can be given intravenously after surgery.
T3 treatment
There is controversy regarding the effects of liothyronine (T3) either on its own or as an adjunct to T4 therapy in the treatment of hypothyroidism. While large scale studies have shown no statistical benefit with the use of T3, there are undoubtedly some patients who do gain symptomatic benefit from the addition of T3, perhaps due to a failure of their own body to efficiently convert the T4 to the biologically more active T3. Taking T3 is more inconvenient as it is a twice daily regime, but as long as patients are carefully monitored to ensure the total amount of thyroid hormone is not excessive, it can be offered as a trial to patients who feel their symptoms are not fully alleviated by T4 alone.
Armour Thyroid and Nature's Thyroid
These are is desiccated extracts of pig thyroid containing both T4 and T3. However, the relative amount of each is uncertain and variable and can lead to marked fluctuations in the blood thyroid hormone levels. Most patients who believe they would be better treated with the use of Armour should try a supervised combination of pure T4 and T3 instead, the doses of which can be more accurately monitored and adjusted. Speak with Dr. Einhorn or Dr. Schneider about this.
Thyroid Nodules and Thyroid Cancer
A thyroid nodule is a small swelling or lump in the thyroid gland. Thyroid nodules are common. These nodules represent either a growth of thyroid tissue or a fluid-filled cyst, which forms a lump in the thyroid gland. Almost half of the population will have tiny thyroid nodules at some point in their lives but, typically, these are not noticeable until they become large and affect normal thyroid size. About 5 percent of people develop significant sized nodules, greater than a centimeter across.
Although most nodules are not cancerous, people who have them should seek medical attention to rule out cancer. Also, some thyroid nodules may produce too much thyroid hormone or become too large, interfering with an individual's breathing or swallowing or causing neck discomfort.
Symptoms and Diagnosis of Thyroid Nodules:
More than 90 percent of thyroid nodules are not harmful or cancerous. An individual may not be aware of the nodule's presence until it starts to grow, resulting in an enlarged thyroid. A doctor may feel it, however, when he or she carefully examines the thyroid gland.
Nodules should be checked by a doctor. Tests can usually tell if a nodule is harmless or harmful and which treatment would be best. A nodule may be cancerous if the lymph nodes under the jaw are swollen and if it grows quickly, feels hard, and causes pain. Cancerous nodules may also cause hoarseness or difficulty with swallowing or breathing, although this is only the case with a small proportion of thyroid cancers.
If a patient has had radiation treatment around the head or neck areas, he or she should tell his or her doctor because this can increase an individual's chances of having nodules and cancer.
Among people who have thyroid nodules, thyroid cancer is found in about 8 percent of men and 4 percent of women. To determine whether a nodule may be harmful and whether the patient should undergo thyroid cancer treatment, the doctor may perform any number of tests. These include the following:
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Ultrasound. A machine is used to show sound waves that map out a picture of the thyroid gland and any nodules contained within it.
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Fine-needle aspiration (FNA) biopsy. In this test, a thin needle is inserted into the nodule to remove cells and/or fluid samples from the nodule for examination under a microscope. Dr. Schneider has vast experience in both thyroid/neck ultrasound and biopsy and performs these procedures in the office, so you get the results right away.
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Thyroid Uptake and Scan. This is a radiation detector that scans over the neck, after a tiny amount of radioactive substance is administered, to reveal whether a nodule is functioning (producing hormones).
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Blood and other laboratory tests. Tests include those that measure levels of thyroid-stimulating hormone, as well as antibodies and possibly calcitonin.