Short Name: TSH
Sample required: Serum
Result Time: 2 HR
Thyroid-stimulating hormone (TSH or thyrotropin) is a glycoprotein secreted by thyrotrophic cells of the anterior pituitary. It consists of two sub-units: the alpha sub-unit which is common to FSH, LH, hCG and TSH, and the beta sub-unit which is biologically specific and antigenically distinct. TSH is part of the bodys feedback system in order to maintain stable amounts of the thyroid hormones thyroxine (T4) and triiodothyronine (T3) in the blood. The TSH test is often the test of choice for evaluating thyroid function and/or symptoms of hyper- or hypothyroidism. Therefore, this test is used to diagnose a thyroid disorder in a person with symptoms (weight loss/gain, tiredness, rapid heart rate, or irregular menstrual periods), screen newborns for an underactive thyroid, monitor thyroid replacement therapy in people with hypothyroidism, diagnose and monitor female infertility problems, help evaluate the function of the pituitary gland (occasionally), and screen adults for thyroid disorders. Generally, TSH levels are extremely ELEVATED in hypothyroid subjects where the test shows excellent discrimiation from normal. Whereas LOW levels are usually associated with hyperthyroidism.