Open Access Articles- Top Results for Euthyroid sick syndrome

Euthyroid sick syndrome

Euthyroid sick syndrome
Classification and external resources
ICD-10 E07.8
ICD-9 790.94
eMedicine med/753
NCI Euthyroid sick syndrome
Patient UK Euthyroid sick syndrome
MeSH D005067

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[1] 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. The most common hormone pattern in sick euthyroid syndrome is a low total and unbound T3 levels with normal T4 and TSH levels.


Causes of euthyroid sick syndrome include a number of acute and chronic conditions, including pneumonia, fasting, starvation, anorexia nervosa, sepsis, trauma, cardiopulmonary bypass, malignancy, stress, heart failure, hypothermia, myocardial infarction, chronic renal failure, cirrhosis, and diabetic ketoacidosis.[1]

Euthyroid sick syndrome (non-thyroidal illness syndrome) has been assumed closely related with a series of diseases, (such as inflammatory bowel disease).[2]


Affected patients may have normal, low, or slightly elevated TSH depending on the spectrum of illness. Total T4 and T3 levels may be altered by binding protein abnormalities, and medications. Reverse T3 levels are generally increased signifying inhibition of normal Type 1 enzyme or reduced clearance of reverse T3. Generally the levels of Free T3 will be lowered, followed by the lowering of Free T4 in relation to severity of the disease. Patients might have high corticosteroid level.


Several trials investigated a possible therapy of ESS. However, they yielded inconsistent and partly contradictory results. This may be caused in the fact that the investigated populations were too heterogeneous in the lack of a consistent definition of non-thyroid illness syndrome..[3]


  1. ^ a b "Euthyroid Sick Syndrome: Thyroid Disorders: Merck Manual Professional". Retrieved 2009-03-29. 
  2. ^ Liu, S; Ren, J; Zhao, Y; Han, G; Hong, Z; Yan, D; Chen, J; Gu, G; Wang, G; Wang, X; Fan, C; Li, J (February 2013). "Nonthyroidal illness syndrome: is it far away from Crohn's disease?". Journal of Clinical Gastroenterology 47 (2): 153–9. PMID 22874844. doi:10.1097/MCG.0b013e318254ea8a. 
  3. ^ Dietrich, JW; Stachon, A; Antic, B; Klein, HH; Hering, S (2008). "The AQUA-FONTIS study: protocol of a multidisciplinary, cross-sectional and prospective longitudinal study for developing standardized diagnostics and classification of non-thyroidal illness syndrome". BMC endocrine disorders 8: 13. PMC 2576461. PMID 18851740. doi:10.1186/1472-6823-8-13. 

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