LTA and hypothyroidism: Hence, establishment of an optimal test protocol and timing of sample collection is of utmost importance.<h4>Case presentation</h4>A 34-year old woman was admitted to our Department because of severe hypothyroidism [on admission thyrotropin (TSH) > 100 μIU/ml, free thyroxine (FT<sub>4</sub>) 0.13 ng/dl (ref. range 0.93-1.7)] despite apparently taking 1000 μg of LT<sub>4</sub> a day.