Free triiodothyronine to free thyroxine ratio in the differential diagnosis of thyrotoxicosis and hyperthyroidism: A retrospective study.

FT3/FT4 ratio helps distinguish GD and DT. In cases of situations where RAIU/scintigraphy and TRAb cannot be studied, the FT3/FT4 ratio is a viable diagnostic tool. Cut-off values with higher specificity can be more helpful in differential diagnosis of GD.