Thyroid Quiz: Test Your Medical IQ

The thyroid gland is located below the Adam's apple in the lower part of the neck and wraps around the windpipe (trachea). The thyroid gland has the shape of a butterfly. The two lobes or "wings" are attached to one another by the middle portion, called the isthmus.

The thyroid gland uses iodine to produce hormones that help regulate the body's metabolism including growth and other functions of the body. The thyroid gland is the only human tissue that actively absorbs and processes iodine from the diet, usually seafood or iodized salt.

The definition of hyperthyroidism is an overactive thyroid gland. As a result, the thyroid gland produces more hormones than the body needs. These high levels of thyroid hormone can lead to weight loss, increased heart rate, and heat intolerance.

Goiter is a non-specific term for enlargement of the thyroid gland. Goiter can be a normal finding or an indicator of thyroid dysfunction. Goiter has become much less common since the widespread use of iodized salt over the past century.

Thyroid storm is a rare medical emergency and requires hospitalization to stabilize the patient. Thyroid storm generally occurs in the context of undiagnosed hyperthyroidism, after several weeks or months of progressively worsening symptoms unrecognized by the affected person or family members until the thyroid storm occurs.

Hypothyroidism, or underactive thyroid, is much more common than hyperthyroidism. Failure of the thyroid to form is the most common cause of hypothyroidism present at birth (congenital hypothyroidism). In older children and adults, the most common cause of hypothyroidism is when the body's white blood cells silently destroy the thyroid in error (called autoimmune thyroiditis). Proper thyroid function is required to maintain normal weight. If you significantly gain or lose weight unintentionally as an adult (for example, more than 10 pounds in 6 months), consult your health-care professional.

In some women, symptoms related to thyroid disorders may be mistaken for those of menopause. Symptoms of hyperthyroidism like menstrual changes or lack of menstruation (amenorrhea), mood swings, hot flashes, and insomnia may be mistaken for menopause symptoms. In addition, women are more likely than men to experience thyroid disorders. Some investigators believe that immune system changes during pregnancy and delivery, may contribute to the higher risk of autoimmune disorders in adult women.

Subtle thyroid disease can be detected by a blood test. Thyroid disease becomes more common with normal aging. Additional risk factors for thyroid disorders include exposure to certain kinds of radiation (for example, radiation therapy for cancer), brain or neck surgery, major head injury, and specific genetic conditions (as examples, Down syndrome, Turner syndrome, type 1 diabetes, lupus, etc.). All adults older than 35 should be screened for thyroid disease every 5 years by simple blood tests. If there is a problem detected, you may see an endocrinologist, a specialist who treats individuals with hormone problems and endocrine gland disorders.

Graves's hyperthyroidism can be treated with medication (methimazole) to suppress the thyroid, radioactive iodine to destroy the thyroid, or surgery to remove the thyroid (called thyroidectomy). The risks, potential benefits, and timing of each approach should be discussed with your endocrinologist or health-care professional based on your specific circumstances. Pediatric patients (younger than 18) with Graves' hyperthyroidism may enter remission with medication alone, thereby avoiding the risks and inconvenience of radioiodine or surgery. However, most adults with Graves' do not respond with medication alone. Radioiodine is preferred as initial therapy for Graves' disease in adults. Permanent hypothyroidism should be expected after radioiodine or thyroidectomy, and hypothyroidism can be conveniently treated with once daily dosing of a small thyroid hormone replacement pill.