Changes

The '''thyroid''' (from the [[Greek]] word for door) is a small endocrine (hormone-producing) organ located in the front of the neck just below your larynx ("Adam's apple").  The thyroid is responsible for regulating many processes in the human body.   

The '''thyroid''' (from the [[Greek]] word for door) is a small [[endocrine]] ([[hormone]]-producing) organ located in the front of the neck just below your [[larynx]] ("Adam's apple").  The thyroid is responsible for regulating many processes in the human body.   

==Function==

==Function==

The thyroid processes '''iodine''' into two hormones: thyroxine (T4) and triiodythyromine (T3).  These two hormones control [[metabolism]].  It also produces calcitonin, which is necessary for calcium absorption.  The thyroid is controlled by the [[pituitary gland]].

The thyroid processes '''[[iodine]]''' into two hormones: [[thyroxine]] (T4) and [[triiodythyromine]] (T3).  These two hormones control [[metabolism]].  It also produces [[calcitonin]], which is necessary for [[calcium]] absorption.  The thyroid is controlled by the [[pituitary gland]].

The pituitary releases '''T'''hyroid '''s'''timulation '''h'''ormone (TSH) in response to T3 and T4 levels circulation in the blood.  If there is an excess of T4, TSH production is diminished; if there isn't enough T4, TSH production is increased.   

The pituitary releases '''T'''hyroid '''s'''timulation '''h'''ormone (TSH) in response to T3 and T4 levels circulation in the blood.  If there is an excess of T4, TSH production is diminished; if there isn't enough T4, TSH production is increased.   

==Iodine==

==Iodine==

Iodine, which is found in many foods, is the essential nutrient in thyroid function.  If one does not consume enough iodine, the thyroid becomes enlarged, which leads to a goiter.  This is the reason that we see ''iodized'' salt—to prevent growth deficiencies related to a lack of iodine in the diet.

Iodine, which is found in many foods, is the essential nutrient in thyroid function.  If one does not consume enough iodine, the thyroid becomes enlarged, which leads to [[goiter]].  This is the reason that we see ''iodized'' salt—to prevent growth deficiencies related to a lack of iodine in the diet.

==Hypo/hyperthyroid==

==Hypo/hyperthyroid==

Hypothyroidism is a lack of T3/T4 in the blood stream;hyperthyroid is an excess.  The chief diagnostic tool for these illnesses is that TSH level.  The TSH level is inversely proportionate to the level of thyroid function (i.e. a high TSH level means an hypoactive thyroid).  Signs and symptoms include:

Hypothyroidism is a lack of T3/T4 in the blood stream; hyperthyroid is an excess.  The chief diagnostic tool for these illnesses is that TSH level.  The TSH level is inversely proportionate to the level of thyroid function (i.e. a high TSH level means an hypoactive thyroid).  Signs and symptoms include:

===Hypothyroid===

===Hypothyroid===

*Paleness

*Paleness

*Weight gain and/or water retention

*Weight gain and/or water retention

*Bradycardia (slow heart rate)

*[[Bradycardia]] (slow heart rate)

Treatment for hypothyroid involves thyroid-hormone replacement therapy (thyroxine).

Treatment for hypothyroid involves thyroid-hormone replacement therapy ([[thyroxine]]).

===Hyperthyroid (Graves disease)===

===Hyperthyroid (Graves disease)===