Tags: Disease.
Euthyroid sick syndrome (ESS) sick euthyroid syndrome (SES) non-thyroidal illness syndrome (NTIS) or low T3 low T4 syndrome is a state of adaptation or dysregulation of thyrotropic feedback control where the levels of T3 and/or T4 are at unusual levels but the thyroid gland does not appear to be dysfunctional. This condition is often seen in starvation critical illness or patients in intensive care unit.