Thyroid Problems

1. Hyperthyroidism Slideshow Pictures
2. Take the Thyroid Disorder Quiz
3. Thyroid Symptoms and Solutions Slideshow Pictures

Medical Author:

Stephanie L Lee, MD, PhD, FACE

Medical Editor:

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, Chief Medical Editor

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.

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Medical Editor:

Jerry R. Balentine, DO, FACEP

Jerry R. Balentine, DO, FACEP

Dr. Balentine received his undergraduate degree from McDaniel College in Westminster, Maryland. He attended medical school at the Philadelphia College of Osteopathic Medicine graduating in1983. He completed his internship at St. Joseph's Hospital in Philadelphia and his Emergency Medicine residency at Lincoln Medical and Mental Health Center in the Bronx, where he served as chief resident.

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• Thyroid Problems Overview
• Hypothyroidism in Pregnancy
• Hyperthyroidism in Pregnancy
• Thyroid Goiter in Pregnancy
• Postpartum Thyroid Disease
• Thyroid Problems Causes
• Thyroid Problems Symptoms
• Hypothyroidism Symptoms in Infants, Children and Adults
• Hyperthyroidism Symptoms in Children, Adults, and Elderly
• Thyroid Nodules and Goiter Symptoms
• When to Seek Medical Care
• Thyroid Problems Diagnosis
• Thyroid Problems Treatment
• Thyroid Problems Medications
• Supplements and Remedies for Thyroid Disease
• Thyroid Surgery
• Follow-up
• Thyroid Problems Prevention
• Thyroid Problems Prognosis
• Synonyms and Keywords
• Authors and Editors
• Thyroid FAQs
• Viewer Comments: Thyroid Disease - Symptoms
• Viewer Comments: Thyroid Disease - Describe Your Experience

The thyroid gland is located on the front part of the neck below the thyroid cartilage (Adam's apple). The gland produces thyroid hormones, which regulate metabolic rate (how fast calories are consumed to produce energy). Thyroid hormones are important in regulating body energy, body temperature, the body's use of other hormones and vitamins, and the growth and maturation of body tissues.

Diseases of the thyroid gland can result in either production of too much (overactive thyroid disease or hyperthyroidism), too little (underactive thyroid disease or hypothyroidism) thyroid hormone, thyroid nodules, and/or goiter. Thyroid problems are much more common in women than in men.

• Production of thyroid hormones: The process of hormone synthesis begins in a part of the brain called the hypothalamus. The hypothalamus releases thyrotropin-releasing hormone (TRH). The TRH travels through the venous plexus located in the pituitary stalk to the pituitary gland, also in the brain. In response, the pituitary gland then releases thyroid-stimulating hormone (TSH, also called thyrotropin) into the blood. The TSH travels to the thyroid gland and stimulates the thyroid to produce the two thyroid hormones, L-thyroxine (T4) and triiodothyronine (T3). The thyroid gland also needs adequate amounts of dietary iodine to be able to produce T4 and T3, the molecules of which contain four and three atoms of iodine, respectively.
• Regulation of thyroid hormone production: To prevent the overproduction or underproduction of thyroid hormones, the pituitary gland senses how much hormone is in the blood and adjust the production of hormones accordingly. For example, when there is too much thyroid hormone in the blood, TRH and TSH production are both decreased. The sum effect of this is to decrease the amount of TSH released from the pituitary gland and to reduce production of thyroid hormones from the thyroid gland to restore the amount of thyroid hormone in the blood to normal. Defects in these regulatory pathways rarely may result in hypothyroidism (underactive thyroid problem) or hyperthyroidism (overactive thyroid problem). The most common cause of hypothyroidism and hyperthyroidism occurs due to problems within the thyroid and not the regulatory system.
• Thyroid goiter: Thyroid goiter is any enlargement of the thyroid that can occur with hyperthyroidism or hypothyroidism but also with benign and malignant (cancerous) nodules. Worldwide, the most common cause of goiter is iodine deficiency. Although it used to be very common in the U.S., it is now less common with the use of iodized salt. Multiple nodules in the thyroid are very common, but only about 5% of the nodules are a thyroid cancer. Thyroid cancer rates have been increasing steadily by about 6% every year for more than 20 years. It is one of the few cancers whose rate is increasing and whose very low rate of mortality is also rising with time. Although radiation exposure as a child can increase the risk of thyroid cancer, we do not know why the overall rate has been increasing. Thyroid cancer is diagnosed after a thyroid ultrasound exam and a needle aspiration biopsy of the nodule.

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