Algorithmic Approach to Hypothyroidism - Differential Diagnosis and Management Framework



Central Hypothyroidism (Secondary or tertiary) ↓TSH, ↓FT4

 • Post-GH therapy, drug-induced

 • Pituitary adenoma

 • Craniopharyngioma

 • Meningioma

 • Glioma

 • Germinoma

 • Immunologic lesions



Overt Hypothyroidism ↑TSH, ↓FT4

 • Initiate LT4

    ≤ 65 yo; no CVD: 1.6 μg/kg daily

    > 65 yo or CVD: 12.5-25 μg daily

 • Measure TSH in 4-6 weeks, Titrate LT4 based on TSH



Subclinical Hypothyroidism ↑TSH, ↔FT4

 • Recheck TSH after 2-3 months and obtain TPOAb



Euthyroid sick syndrome ↔TSH, ↓FT3/↓FT4

 • Treat acute illness



Matthew Ho, MD PhD @MatthewHoMD



#Hypothyroidism #Differential #Diagnosis #algorithm #endocrinology #hypothyroid #Management