What Are The Three Types Of Goiter?

A goiter is any visible enlargement of the thyroid gland.

The thyroid gland, straddling the trachea (windpipe), produces thyroxin, a hormone that regulates the metabolic activity of the body. The thyroid is controlled by the pituitary gland, which secretes thyroid stimulating hormone (TSH) in response to the amount of thyroxin it finds in the blood. TSH increases the amount of thyroxin secreted by the thyroid and also causes the thyroid gland to grow.

Too much thyroxin increases the metabolism, causing weight loss, temperature elevation, nervousness, and irritability. Too little thyroxin slows the metabolism down, deepens the voice, causes weight gain and water retention, and retards growth and mental development in children. Both conditions also alter hair and skin growth, bowel function, and menstrual flow. The thyroid gland is often enlarged whether it is making too much hormone, too little, or sometimes even when it is functioning normally.

The Three Types of Goiter

• Hyperthyroid goiter--If the amount of stimulating hormone is excessive, the thyroid will both enlarge and secrete too much thyroxin. The result--hyperthyroidism with a goiter. Graves' disease is the most common form of this disorder.
• Euthyroid goiter--The thyroid is the only organ in the body to use iodine. If dietary iodine is slightly inadequate, too little thyroxin will be secreted, and the pituitary will sense the deficiency and produce more TSH. The thyroid gland will enlarge enough to make sufficient thyroxin. This form of goiter does not alter thyroid function in any significant way.
• Hypothyroid goiter--If dietary iodine is severely reduced, even an enlarged gland will not be able to make enough thyroxin. The gland will keep growing under the influence of TSH, but it may never be able to make enough thyroxin.