Figure 1
Schema showing the general changes that occur in serum thyroid-related hormones following illness of varying severity. The yellow area represents the reference range. The changes for free T4 and free T3 represent those found using either ultrafiltration or equilibrium dialysis of serum with low sample dilution. Publications that use methods for free hormone measurement that are unreliable in situations of low serum hormone binding capacity tend to follow the same profile as for total T3 and total T4 (see text for full explanation).
