The thyroid is an endocrine gland in the front of the neck, consisting of two lobes connected by an isthmus. It secretes hormones, which primarily influence the metabolic rate and protein synthesis. The hormones also have many other effects including those on development. The thyroid hormones triiodothyronine (T3) and thyroxine (T4) are created from iodine and tyrosine. It also produces the hormone calcitonin, which plays a role in calcium homeostasis.
Thyroid disorders are abnormalities because of hyper or hyposecretions of its respective hormones.
Goiter - A goiter simply describes an enlargement of the thyroid gland. It may be associated with hypothyroidism, hyperthyroidism, or normal thyroid function.
Hypothyroidism - Hypothyroidism results from the thyroid gland producing an insufficient amount of thyroid hormone. It can develop from problems within the thyroid gland, pituitary gland, or hypothalamus
Thyroid cancer - Thyroid cancer is far more common among adult women than men or youth. About 2/3 of cases occur in people under age 55. There are different kinds of thyroid cancer, depending upon the specific cell type within the thyroid that has become cancerous. Most cases of thyroid cancer have a good prognosis and high survival rates, especially when diagnosed in its early stages.
Thyroid Nodules - Nodules are lumps or abnormal masses within the thyroid. Nodules can be caused by benign cysts, benign tumors, or, less commonly, by cancers of the thyroid. Nodules may be single or multiple and can vary in size. If nodules are excessively large, they may cause symptoms related to compression of nearby structures.
Hyperthyroidism - Hyperthyroidism describes excessive production of thyroid hormone, a less common condition than hypothyroidism. Symptoms of hypothyroidism usually relate to increased metabolism. In mild cases, there may not be apparent symptoms.