The thyroid is a large endocrine gland found in the neck within the human body. It regulates the speed at which energy is burned and protein is made, as well as the sensitivity the body should have toward other hormones. When thyroid problems affect an individual, different diseases can be present.

Producing its own hormones is the thyroid's way of accomplishing this. Such hormones produced are triiodothyronine (T₃), thyroxine (T₄) and calcitonin. Iodine is required for T₃ and T₄, which control metabolism and affect growth of body systems. Calcitonin assists in maintaining proper calcium levels in the body (known as calcium homeostasis or calcium metabolism).

With the thyroid's important functions and role in the body, problems can arise when it is not healthy or for any reason not working properly. There are several categories of thyroid disease:

Hypothyroidism (underactive thyroid function)

Hyperthyroidism (overactive thyroid function)

Anatomical disorders

Tumors (including thyroid cancer)

Each major category holds several unique thyroid problems. Some maladies are more severe than others, and some may be more difficult to relieve, treat or even prevent. Diagnosis and treatment may vary from one specific thyroid disease to the other.

Left untreated, thyroid problems may lead to other conditions and symptoms such as raised cholesterol levels, heart disease, muscle weakness, infertility and osteoporosis. Finally, it may result in coma or death for the patient.

Thyroid Facts:

Some thyroid diseases are autoimmune, including the more common Graves' disease (hyperthyroidism) and Hashimoto's thyroiditis (hypothyroidism).

The thyroid itself is controled by the hypothalamus (link between endocrine and nervous systems) and hypophysis (pituitary gland).

The Greek word that spawned thyroid, Thyreos, means "shield."

The common human thyroid weighs between 12 and 20 grams, and its shape is reminiscent of a butterfly.

In 1656, English anatomist Thomas Warton was the first to identify the thyroid in modern times. Wharton's duct now holds his name.