Thyroid Tests Interpretation

Published by NHC on April 14, 2021April 14, 2021

Thyroid Tests Interpretation (TSH, T3, T4, rT3, Thyroid Antibodies)

	High	Low
TSH (Thyroid Stimulating Hormone)	Hashimoto’s Thyroiditis Iodine deficiency Large doses of iodine Goitrogenic foods Excessive stress and cortisol Obesity Thyroiditis Severe and chronic illness Pituitary tumour Medications: Antithyroid medications Lithium Potassium iodide	Graves disease Pituitary dysfunction Certain tumours Severe illness Medications: Aspirin Dopamine Heparin Steroids Levothyroxine
T4 (Thyroxine)	Graves disease Pregnancy Hepatitis Thyroid cancer Acute thyroiditis Toxic thyroid nodule Medications: Aspirin Danazol Heparin Clofibrate Oestrogens Heroin Oral contraceptives Levothyroxine	Hashimoto’s thyroiditis Nutritional deficiency: Iodine Iron Selenium Tyrosine Renal failure Cushings syndrome Cirrhosis Mediations: Furosemide Methadone Phenytoins Rifampicin Anabolic steroids Androgens Antithyroid drugs Lithium Phenytoin T3 medication
T3 (Triiodothyronine)	Graves disease Pregnancy Hepatitis Thyroid cancer Acute thyroiditis Toxic thyroid nodule Medications: Oestrogens Methodone Oral contraceptives	Hashimoto’s thyroiditis Nutritional deficiency: Iodine Iron Selenium Tyrosine Inflammation Stress Obesity Renal failure Cushings syndrome Cirrhosis Liver diseases Mediations: Anabolic steroids Androgens Lithium Phenytoin Propranolol Salicylates (high dose) Reserpine
rT3 (Reverse Triiodothyronine)	Stress Inflammation Elevated cortisol Trauma Anorexia nervosa Hepatic dysfunction Iron deficiency
Antithyroid peroxidase Antibody (Anti-TPO, TPO-Ab, Thyroid Autoantibody)	Hashimotos thyroiditis Graves disease Rheumatoid arthritis Rheumatoid-collagen disease Pernicious anaemia Thyroid cancer
Antithyroglobulin Antibody (Thyroid Autoantibody)	Hashimotos thyroiditis Graves disease Rheumatoid arthritis Rheumatoid-collagen disease Pernicious anaemia Thyroid cancer
TBG (Thyroid Binding Globulin)	Pregnancy Oral contraceptives Oestrogen replacement therapy Oestrogen producing tumours Infectious hepatitis	Hypoproteinaemia Malnutrition Malabsorption Ovarian failure Testosterone producing tumours Excessive stress

References

Pagana, K. D., & Pagana, T. J. (2019). Mosby’s Diagnostic and Laboratory Test Reference (14th ed.) Elsevier Health Sciences

Williamson, M. A., Snyder, L. M., & Wallach, J. B. 1. (2011). Wallach’s interpretation of diagnostic tests. (9th ed.) Philadelphia: Wolters Kluwer/Lippincott Williams & Wilkins.