The thyroid gland is a small, 2-inch gland located in the front of the neck, just below the voice box. It has a butterfly-shaped appearance and consists of two lobes. The Baptist Health Systems reports that approximately 14 million people in the U.S. suffer from thyroid dysfunction, and thyroid dysfunction is seven times more likely to occur in women than in men.
Thyroid Gland Function
The thyroid is made up of follicular cells and parafollicular cells. The follicular cells secrete iodine-containing hormones called thyroxine, T4, and triiodothyronine, T3. The parafollicular cells produce the hormone calcitonin. The thyroid’s role is to regulate the body’s metabolism and calcium balance. The University of Maryland Medical Center states that the hormones T3 and T4 stimulate the tissues in the body to make protein and increase the amount of oxygen used by cells.
Hyperthyroidism occurs when the thyroid produces too much thyroxine. Symptoms of hyperthyroidism include sudden weight loss, rapid heartbeat, increased appetite, nervousness, anxiety, tremor, sweating, fatigue, intolerance to heat and difficulty sleeping. Older adults may have subtle symptoms or may not have any symptoms at all. The Mayo Clinic states that the most common cause of hyperthyroidism is an autoimmune disorder called Grave’s disease. In Grave’s disease, antibodies attack the thyroid and cause the gland to produce too much T4. Small, noncancerous growths can also cause the thyroid to produce too much T4. Another cause of hyperthyroidism is thyroiditis, which causes the thyroid gland to become inflamed.
Hypothyroidism can occur when the thyroid does not produce an adequate amount of thyroid hormone. Women over the age of 50 are most likely to develop hypothyroidism. Symptoms of hypothyroidism appear gradually and include fatigue, sluggishness, sensitivity to cold, constipation, dry skin, puffy face, weight gain, muscle weakness, brittle fingernails and brittle hair. Hashimoto’s disease, an autoimmune disorder that attacks the thyroid, is the most common case of hypothyroidism, notes the Mayo Clinic. People who are treated with antithyroid hormones for hyperthyroidism can develop hypothyroidism. Radiation to treat cancer, certain medications and thyroid surgery can diminish hormone production, which causes hypothyroidism.
A diagnosis of hyperthyroidism or hypothyroidism is based on symptoms and blood tests. Blood tests are used to determine the level of thyroid stimulating hormone, TSH, and levels of thyroxine, T4. A low T4 level and high level of TSH indicates an underactive thyroid. High levels of thyroxine and low levels of TSH indicate hyperthyroidism.
Radioactive iodine causes the thyroid gland to shrink and eliminates symptoms of hyperthyroidism, usually within four to six months. Antithyroid medications, beta blockers and surgery to remove most of the thyroid gland are also treatments for hyperthyroidism. Doctors treat hypothyroidism with a synthetic thyroid medication. The Mayo Clinic states that within one to two weeks of starting medication, most people become less fatigued and symptoms gradually decrease within the next few weeks of treatment; however, blood tests to check thyroid hormone levels are performed every two to three months to make sure the right dose of medication is being given