The thyroid is a butterfly-shaped organ located in the neck just below the thyroid cartilage (Adam’s apple). It gets its name from the G reek word for “shield,” after the shape of the related cartilage. The thyroid produces thyroid hormone, which helps control the body’s metabolism by regulating how quickly the body uses energy. Thyroid hormone also controls how sensitive the body is to other hormones. Important thyroid dis.eases include hyperthyroidism, hypothyroidism, thyroid nodules and cancer.
In hyperthyroidism, the thyroid produces more hormone than the body needs. It is more likely to affect women, and is more common in younger persons. More than 70% of hyperthyroidism is caused by Graves’ disease, an autoimmune disorder in which antibodies are produced that attack the thyroid and release extra hormone. Another cause is toxic nodular goiter, where multiple thyroid nodules enlarge the gland and produce excess hormone. Thyroiditis, inflammation of the thyroid, can cause initial increased hormone levels, followed by decreased levels. Post-partum thyroiditis occurs in 5% of women following childbirth. This produces initial hyperthyroidism, with subsequent hypothyroidism. The majority of these women return to normal function.
Hyperthyroidism caused by Craves’ disease or toxic nodular goiter is most often treated with a single dose of radioactive iodine. Given in pill form in the Nuclear .Medicine Department, this iodine is taken up by the thyroid, where the localized radioactivity eventually removes all thyroid tissue from the neck. Once this happens, a daily dose of thyroid hormone (Synthroid) will need to be taken.
Symptoms of hyperthyroidism:
Weight loss, rapid heart rate, heat intolerance and sweating, nervousness, tremors.
Hypothyroidism occurs when insufficient thyroid hormone is produced. It develops in about 5% of the population and is most common in women older than 60 years. Hashimoto’s thyroiditis, an autoimmune condition, is the most common cause. Hypothyroidism can also be caused by certain drugs, particularly lithium and the heart medication amiodarone. Once detected by laboratory data, hypothyroidism can be treated with a daily dose of thyroid hormone.
Symptoms of hypothyroidism:
Weight gain, cold intolerance, dry hair and skin, decreased sex drive, fatigue, depression.