Thyroid: is a gland in the lower portion of the neck that produces thyroid hormone and calcitonin.
The thyroid gland is a butterfly shaped organ that wraps around the front parts of our windpipe (trachea) and feeding pipe (esophagus), just below the Adam's apple.
Thyroid hormone: develops mainly from the iodine that we consume with our daily nutrition.
Thyroid hormones regulate multiple systems in the body including; heart, cholesterol metabolism, energy levels, fertility, digestion, and other important functions.
Calcitonin: plays a role in calcium metabolism.
Thyroid hormone production is regulated by the pituitary gland (master gland in the brain).
During the first trimester of pregnancy, maternal thyroid hormone controls development of important organs (brain, nervous system) in the fetus. Fetal thyroid does not begin functioning until the end of the first trimester. After that, the fetus depends on maternal iodine intake to produce adequate amount of thyroid hormone. Therefore pregnant women need to maintain an adequate (about 200 microgram/day) iodine intake during the pregnancy.
Under-active thyroid hypothyroidism: a condition where your thyroid gland does not produce enough thyroid hormone to meet your body's needs. Since thyroid hormone controls all energy metabolism in our body, as well as our nervous, digestive, cardiovascular, reproductive and other important systems in our body; symptoms of under-active thyroid may include: weight gain, fatigue, loss of memory and concentration, dry skin, hair loss, constipation, irregular menstrual cycles, and feeling cold all the time. Hypothyroidism is typically caused by inflammation of the thyroid gland, thyroiditis, but can occur after thyroid surgery, treatment with radioactive iodine, insufficient iodine intake and other conditions and medications (example: amiodarone). Treatment includes administration of synthetic thyroid hormone, thyroxine.
Thyroid inflammation, thyroiditis, can be caused, most of the time, by antibodies that stimulate or suppress thyroid hormone production, leading to over, or under-active, thyroid. The symptoms of this are related to the degree and type of thyroid dysfunction, and can manifest as pain in the neck, or enlarged thyroid. Not everybody with thyroiditis can have abnormally functioning thyroid. Treatment of thyroiditis depends on the nature of inflammation, degree, and type of thyroid dysfunction.
Over-active thyroid hyperthyroidism is a condition, when your thyroid gland produces too much of thyroid hormone. Excess of thyroid hormone may lead to rapid weight loss, despite increased appetite, fast heart beats, hand shakes, frequent bowel movements, hair loss, feeling hot all the time, irregular menstrual cycles, and other symptoms. Over active thyroid can be caused by thyroid inflammation, antibodies that stimulate thyroid, Graves disease, or overactive thyroid nodules. Treatment can include thyroid medications, radioactive iodine, or thyroid surgery. Some patients with overactive thyroid can develop thyroid eye disease.
Radioactive iodine: thyroid gland uses iodine to make thyroid hormones and it is the only organ in the body that takes up and accumulates iodine. Radioactive isotopes of iodine are used for testing of thyroid function (thyroid uptake and scan), identification of thyroid cancer spread, recurrence (iodine whole body scan), or treatment of thyroid cancer or overactive thyroid. Physicians who administer radioactive iodine will discuss indications and risks with a patient who is considered a candidate for radioactive iodine treatment or diagnostic procedure.
Thyroid nodule: a localized growth within thyroid gland. It can be filled with solid tissue (solid nodule), fluid (cystic nodule), or a mixture of both (mixed nodule). Many people have thyroid nodules (either one nodule, or many- multinodular goiter), but only 4-5% of nodules are cancerous. Thyroid nodules can produce too much thyroid hormone- hot nodules, or be metabolically inactive- cold nodules, but both types can potentially contain cancer. Nodules that are big (more than 1 cm), solid or mixed in nature, rapidly growing, or have concerning radiographic characteristics typically undergo aspiration biopsy to determine if they contain cancer.
Thyroid cancer: typically diagnosed as a result of the thyroid nodule biopsy, but can be an accidental finding during thyroid surgery, preformed for the big thyroid gland(goiter). Prognoses for most cases of thyroid cancer is usually excellent, with 95% chance to be alive 10 years after diagnosis. Risk factors to develop thyroid cancer include; prior therapeutic radiation to the head/neck area, and family history of thyroid cancer. Treatment includes removal of thyroid gland and any affected lymph nodes in the neck, in some cases treatment with radioactive iodine, and use of thyroid hormone to prevent regrowth of thyroid gland. During the evaluation for thyroid cancer, patients may be asked to follow a diet that's low in iodine to improve diagnostic accuracy or effectiveness of treatment.
Thyroid biopsy: a procedure when content of the thyroid nodule (or parathyroid gland or lymph node next to thyroid) is aspirated (taken) for analysis, to check for cancer. During the procedure, the patient is placed on their back with a pillow placed under their shoulder blades so that the neck is stretched out and the thyroid becomes more accessible. After skin on the neck is cleaned and numbed with anesthetic, a very fine needle is inserted in the area of interest. At least three passes are taken to obtain an adequate amount of cells that is necessary to make a correct diagnosis. After that, skin is cleaned and an ice pack is applied to minimize any bruising in the neck. As with any biopsy, complications include: bleeding/bruising at the side of the biopsy. The physician, prior to performing the procedure, will discuss indications and possible complications of the procedure, and what to do afterwards. Overall procedure lasts about 30 min and no specific preparations are required, except some patients may be asked not to take medications that can increase chance of bleeding for several days prior to procedure.