Ruchi Mathur, MD, FRCP(C) is an Attending Physician with the Division of Endocrinology, Diabetes and Metabolism and Associate Director of Clinical Research, Recruitment and Phenotyping with the Center for Androgen Related Disorders, Department of Obstetrics and Gynecology at Cedars-Sinai Medical Center.
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
The thyroid is a gland that makes and stores essential
hormones that help
regulate the heart rate, blood pressure, body
temperature, and the rate of chemical reactions (metabolism) in the body. It is
located in the anterior neck
just below the Adams apple.
The thyroid gland is the, is the main part of the
body that takes up iodine. In a thyroid scan, iodine is labeled with a
radioactive tracer, and a special camera is used to measure how much tracer is
absorbed from the bloodstream by the thyroid gland. If a patient is allergic to
iodine, technetium can be used as an alternative.
How is the thyroid scan performed?
A thyroid scan is an outpatient procedure usually done
in the nuclear medicine section of a hospital. This is usually part of the
radiology
department.
If you have a thyroid scan, you will be asked to take a
drink, or swallow a pill containing the iodine. You will then wait for the iodine to be
taken up by the thyroid - usually about 4 hours. At this time you lie under a
scintography camera, and it will take pictures which correlate directly to the
amount of iodine taken up by the thyroid. This is done by counting the intensity
and location of the gamma rays emitted by the radioactively labeled iodine. You
then leave the hospital, and return in 24 hours to have a second scan performed
in the same manner.
There are no limitations during this 24 hour interval except
that you will be asked to take precautions when you urinate. This is because the
radioactive iodine is
removed from your body by the urine, and it is safer to have others avoid
contact with your urine during this time. Be sure to let the doctor performing
the test know if you have a iodine allergy, or if you have
ingested a lot of iodine-containing foods (like sushi) prior to the test.
Hypothyroidism is any state in which thyroid hormone production is below normal. Normally, the
rate of thyroid hormone production is controlled by the brain at the pituitary.
Hypothyroidism is a very common condition and the symptoms of hypothyroidism are
often subtle.
Hyperthyroidism is an excess of thyroid hormone resulting from an overactive thyroid gland. Symptoms can include increased heart rate, weight
loss, depression, and cognitive slowing. Treatment is by medication, the use of
radioactive iodine, thyroid surgery, or reducing the dose of thyroid hormone.
There are four major types of thyroid cancer: papillary, follicular, medullary, and anaplastic thyroid cancer. Tumors on the thyroid are referred to as thyroid nodules. Symptoms of thyroid cancer include swollen lymph nodes, pain in the throat, difficulty swallowing, hoarseness, and a lump near the Adam's apple. Treatment usually involves chemotherapy, surgery, radioactive iodine, hormone treatment or external radiation and depends upon the type of thyroid cancer, the patient's age, the tumor size, and whether the cancer has metastasized.
Hashimoto's thyroiditis is the most common cause of hypothyroidism in the US. This conditions is caused by inflammation of the thyroid gland. Symptoms may include: fatigue, weight gain, cold intolerance, excessive sleepiness, dry or coarse hair, difficulty swallowing, a lump in the front of the throat, and many more. Treatment is usually hypothyroid medication.
Thyroid nodules are the most common endocrine problem in the United States. The term "thyroid nodule" refers to any abnormal growth that forms a lump in the thyroid gland. The vast majority of thyroid nodules are benign.
There are many types of thyroid disease. Some occur due to the function of the thyroid itself such as hypothyroidism, hyperthyroidism, Hashimoto's thyroiditis, etc. Some causes of thyroid disease occur due to problems with the structure of the thyroid gland such as goiters, thyroid nodules, and thyroid cancer. Treatment of thyroid disease depends on the cause of the disease.
Graves' disease is an autoimmune disease that affects the thyroid. Some of the symptoms of Graves' disease include hand tremors, rapid heartbeat, trouble sleeping, enlarged thyroid, thinning of the skin or fine brittle hair. Causes of Graves' disease are thought to be multifactorial such as genes, gender, stress, and infection. Treatment for Graves' disease is generally medication.
Thyroiditis is the inflammation of the thyroid gland. The inflamed thyroid gland can release an excess of thyroid hormones into the blood stream, resulting in a temporary hyperthyroid state. Some forms of thyroiditis can be diagnosed based on tenderness and enlargement of the thyroid gland. A thyroid scan sometimes is used in making the diagnosis. Thyroiditis can also be diagnosed with a biopsy of the thyroid gland.
Hyperthyroidism is a condition in which an overactive thyroid gland is producing an excessive amount of
thyroid hormones
that circulate in the
blood. ("Hyper" means "over" in Greek). Thyrotoxicosis is a toxic condition that is caused by
an excess of thyroid hormones from any cause. Thyrotoxicosis can be caused by
an excessive intake of thyroid hormone or by overproduction of thyroid hormones by the thyroid gland. Because both physicians and patients
often use these words interchangeably, we will take some liberty by using the
term "hyperthyroidism" throughout this article.
What are thyroid hormones?
Thyroid hormones stimulate the metabolism of cells. They are produced by the
thyroid gland. The thyroid gland is located in the lower part of the neck, below the Adam's apple. The gland wraps around the
windpipe (trachea) and has a shape that is similar to a butterfly formed by two
wings (lobe...