Abnormalities that can affect TSH levels include hyperthyroidism, primary hypothyroidism and secondary hypothyroidism, explains The American Thyroid Association. These disorders can be caused by a pituitary gland dysfunction or problems with the thyroid gland.Continue Reading
Primary diseases affect the thyroid gland and secondary diseases are due to problems in the pituitary gland, according to The American Thyroid Association. The first test that doctors use to assess thyroid function is the thyroid panel, which measures the quantity of TSH and thyroid hormone in the blood. Patient with hyperthyroidism and secondary hypothyroidism have low TSH levels and patients with primary hypothyroidism have elevated levels of TSH.
Common causes of hyperthyroidism include Grave���s disease, toxic adenomas, subacute thyroiditis, pituitary gland dysfunction and thyroid cancer, explains WebMD. Disease that cause hypothyroidism include Hashimoto���s thyroiditis, removal of the thyroid gland, exposure to excessive amounts of iodine, and lithium.
TSH is a hormone that is regulated by a complex interaction between the hypothalamus, pituitary gland and thyroid gland, explains MedicineNet. The hormone is released by the pituitary gland in the brain and regulates thyroid hormone production in the thyroid gland. When too much thyroid hormone is in the blood, the pituitary gland reduces the secretion of TSH and when thyroid hormone levels drop, the pituitary increases TSH secretion.Learn more about Medical Ranges & Levels