More about Hyper and Hypothyroidism

The thyroid is a small, butterfly-shaped gland located at the base of your neck just below the Adam’s apple. It’s part of an intricate network of glands called the endocrine system. The endocrine system is responsible for coordinating many of your body’s activities. The thyroid gland manufactures hormones that regulate your body’s metabolism. Several different disorders can arise when your thyroid produces too much hormone (hyperthyroidism) or not enough (hypothyroidism). Four common disorders of the thyroid are Hashimoto’s thyroiditis, Graves’ disease, goiter, and thyroid nodules.

HYPER (overactive) thyroid / Grave's Disease / Goiter

In hyperthyroidism, the thyroid gland is overactive. It produces too much of its hormone. Hyperthyroidism affects about 1 percent of women. It’s less common in men.

Graves’ disease is the most common cause of hyperthyroidism, affecting about 70 percent of people with an overactive thyroid. Nodules on the thyroid — a condition called toxic nodular goiter or multinodular goiter — can also cause the gland to overproduce its hormones. Excessive thyroid hormone production leads to symptoms such as: Restlessness; Nervousness; Racing heart; Irritability; Increased sweating; Shaking and Anxiety. A blood test measures levels of thyroid hormone (thyroxine, or T4) and thyroid-stimulating hormone (TSH) in your blood. The pituitary gland releases TSH to stimulate the thyroid to produce its hormones. High thyroxine and low TSH levels indicate that your thyroid gland is overactive. Your doctor might also give you radioactive iodine by mouth or as an injection, and then measure how much of it your thyroid gland takes up. Your thyroid takes in iodine to produce its hormones. Taking in a lot of radioactive iodine is a sign that your thyroid is overactive. The low level of radioactivity resolves quickly and isn’t dangerous for most people.

Graves’ disease was named for the doctor who first described it more than 150 years ago. It’s the most common cause of hyperthyroidism in the United States, affecting about 1 in 200 people. Graves’ is an autoimmune disorder that occurs when the body’s immune system mistakenly attacks the thyroid gland. This can cause the gland to overproduce the hormone responsible for regulating metabolism. The disease is hereditary and may develop at any age in men or women, but it’s much more common in women ages 20 to 30, according to the Department of Health and Human ServicesTrusted Source. Other risk factors include stress, pregnancy, and smoking. When there’s a high level of thyroid hormone in your bloodstream, your body’s systems speed up and cause symptoms that are common to hyperthyroidism. A simple physical exam can reveal an enlarged thyroid, enlarged bulging eyes, and signs of increased metabolism, including rapid pulse and high blood pressure. Your doctor will also order blood tests to check for high levels of T4 and low levels of TSH, both of which are signs of Graves’ disease. A radioactive iodine uptake test might also be administered to measure how quickly your thyroid takes up iodine. A high uptake of iodine is consistent with Graves’ disease.

Goiter is a noncancerous enlargement of the thyroid gland. The most common cause of goiter worldwide is iodine deficiency in the diet. Researchers estimate that goiter affects 200 million of the 800 million people who are iodine-deficient worldwide. Conversely, goiter is often caused by — and a symptom of — hyperthyroidism in the United States, where iodized salt provides plenty of iodine. Goiter can affect anyone at any age, especially in areas of the world where foods rich in iodine are in short supply. However, goiters are more common after the age of 40 and in women, who are more likely to have thyroid disorders. Other risk factors include family medical history, certain medication usage, pregnancy, and radiation exposure. There might not be any symptoms if the goiter isn’t severe. Your doctor will feel your neck area and have you swallow during a routine physical exam. Blood tests will reveal the levels of thyroid hormone, TSH, and antibodies in your bloodstream. This will diagnose thyroid disorders that are often a cause of goiter.

HYPO (underactive) thyroid / Hashimoto's

Hypothyroidism is the opposite of hyperthyroidism. The thyroid gland is underactive, and it can’t produce enough of its hormones. Hypothyroidism is often caused by Hashimoto’s thyroiditis, surgery to remove the thyroid gland, or damage from radiation treatment. In the United States, it affects around 4.6 percent of people 12 years old and older. Most cases of hypothyroidism are mild. Too little thyroid hormone production leads to symptoms such as: Fatigue; Dry skin; Increased sensitivity to cold; Memory problems; Constipation; Depression and/or Weight gain. Your doctor will perform blood tests to measure your TSH and thyroid hormone levels. A high TSH level and low thyroxine level could mean that your thyroid is underactive. These levels could also indicate that your pituitary gland is releasing more TSH to try to stimulate the thyroid gland to make its hormone. The main treatment for hypothyroidism is to take thyroid hormone pills. It’s important to get the dose right, because taking too much thyroid hormone can cause symptoms of hyperthyroidism. Hashimoto’s thyroiditis is also known as chronic lymphocytic thyroiditis. It’s the most common cause of hypothyroidism in the United States, affecting about 14 million Americans. It can occur at any age, but it’s most common in middle-aged women. The disease occurs when the body’s immune system mistakenly attacks and slowly destroys the thyroid gland and its ability to produce hormones. Some people with mild cases of Hashimoto’s thyroiditis may have no obvious symptoms. The disease can remain stable for years, and symptoms are often subtle. They’re also not specific, which means they mimic symptoms of many other conditions. Testing the level of TSH is often the first step when screening for any type of thyroid disorder. Your doctor might order a blood test to check for increased levels of TSH as well as low levels of thyroid hormone (T3 or T4) if you’re experiencing some of the above symptoms. Hashimoto’s thyroiditis is an autoimmune disorder, so the blood test would also show abnormal antibodies that might be attacking the thyroid.

Thyroid Nodules are growths that form on or in the thyroid gland. An ultrasound of the thyroid can check for swelling or nodules. About 1 percent of men and 5 percent of women living in iodine-sufficient countries have thyroid nodules that are large enough to feel. About 50 percent of people will have nodules that are too tiny to feel. The causes aren’t always known but can include iodine deficiency and Hashimoto’s thyroiditis. The nodules can be solid or fluid-filled. Most are benign, but they can also be cancerous in a small percentage of cases. As with other thyroid-related problems, nodules are more common in women than men, and the risk in both sexes increases with age.