About the test
Thyroid stimulating hormone (TSH) is a glycoprotein synthetized in the anterior pituitary gland. The TSH test is used to evaluate the thyroid gland’s function.
TSH stimulates the thyroid gland to produce thyroxin and triiodothyronine which, in turn, stimulates metabolism of all body tissues.
TSH values are often evaluated along with Τ4 values for the differential diagnosis of primary and secondary hypothyroidism.
Sample
Venous blood
Preparation
No specific preparation is required. In case the examinee is under hormonal therapy, the test should be performed before taking the dose.
Procedure
Venipuncture
Increased values
- Primary hypothyroidism
- Hashimoto thyroiditis
- Partial thyroidectomy
- Pituitary adenoma
- Addison’s disease
- Eclampsia
- Hyperpituitarism
- Pituitary adenoma
- Thyroid hormone resistance syndrome
- Drugs: (Amiodarone, morphine, lithium, clomiphene, methimazole)
Decreased values
- Hashimoto thyroiditis
- Hyperthyroidism
- Secondary hypothyroidism
- οργανικό εγκεφαλικό σύνδρομο
- Φάρμακα: (Ασπιρίνη, ντοπαμίνη, γλυκοκορτικοειδή, ηπαρίνη, κετοκοναζόλη, θυρεοειδικές ορμόνες)
Additional Information
- TSH levels are subject to a diurnal variation. Lower levels are documented around 10a.m. and higher ones around 10p.m.
- Falsely decreased TSH levels may be noticed during the first trimester of pregnancy, due to elevated beta chorionic gonadotropin.