Approach to the Diagnosis of Hyperthyroidism - Differential Diagnosis and Workup Algorithm



 • Secondary Hyperthyroidism (↑↔TSH,  ↑Total T3/Free T4)

 • Subclinical Hyperthyroidism (↓TSH,  ↔Total T3/Free T4)

 • Overt Hyperthyroidism (↓TSH,  ↑Total T3/Free T4)

 • ß-hCG-associated Hyperthyroidism (↑↑↑ ß-hCG)

 • Hyperthyroidism unlikely (↔TSH,  ↔Total T3/Free T4)



Radioactive Iodine Scan - High Uptake:

 • Graves disease

 • Low iodine state, Gestational trophoblastic disease

 • Toxic adenoma, Multinodular goiter

Radioactive Iodine Scan - Low Uptake:

 • Early Hashimoto thyroiditis (i.e., hashitoxicosis)

 • Thyroiditis, Iodine (e.g. contrast), Struma ovarii, Amiodarone

 • Exogenous thyroid hormone use



Matthew Ho, MD PhD @MatthewHoMD



#Hyperthyroidism #Differential #Diagnosis #Algorithm #endocrinology