Euthyroid sick syndrome
Encyclopedia
Euthyroid sick syndrome, sick euthyroid syndrome, non-thyroidal illness syndrome 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.
, starvation
, sepsis
, trauma
, cardiopulmonary bypass, malignancy, stress
, heart failure, hypothermia
, myocardial infarction
, chronic renal failure
, cirrhosis
, and diabetic ketoacidosis
.
abnormalities, and medications. Reverse T3 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.
Causes
FastingFasting
Fasting is primarily the act of willingly abstaining from some or all food, drink, or both, for a period of time. An absolute fast is normally defined as abstinence from all food and liquid for a defined period, usually a single day , or several days. Other fasts may be only partially restrictive,...
, starvation
Starvation
Starvation is a severe deficiency in caloric energy, nutrient and vitamin intake. It is the most extreme form of malnutrition. In humans, prolonged starvation can cause permanent organ damage and eventually, death...
, sepsis
Sepsis
Sepsis is a potentially deadly medical condition that is characterized by a whole-body inflammatory state and the presence of a known or suspected infection. The body may develop this inflammatory response by the immune system to microbes in the blood, urine, lungs, skin, or other tissues...
, trauma
Physical trauma
Trauma refers to "a body wound or shock produced by sudden physical injury, as from violence or accident." It can also be described as "a physical wound or injury, such as a fracture or blow." Major trauma can result in secondary complications such as circulatory shock, respiratory failure and death...
, cardiopulmonary bypass, malignancy, stress
Stress (biology)
Stress is a term in psychology and biology, borrowed from physics and engineering and first used in the biological context in the 1930s, which has in more recent decades become commonly used in popular parlance...
, heart failure, hypothermia
Hypothermia
Hypothermia is a condition in which core temperature drops below the required temperature for normal metabolism and body functions which is defined as . Body temperature is usually maintained near a constant level of through biologic homeostasis or thermoregulation...
, myocardial infarction
Myocardial infarction
Myocardial infarction or acute myocardial infarction , commonly known as a heart attack, results from the interruption of blood supply to a part of the heart, causing heart cells to die...
, chronic renal failure
Chronic renal failure
Chronic kidney disease , also known as chronic renal disease, is a progressive loss in renal function over a period of months or years. The symptoms of worsening kidney function are unspecific, and might include feeling generally unwell and experiencing a reduced appetite...
, cirrhosis
Cirrhosis
Cirrhosis is a consequence of chronic liver disease characterized by replacement of liver tissue by fibrosis, scar tissue and regenerative nodules , leading to loss of liver function...
, and diabetic ketoacidosis
Diabetic ketoacidosis
Diabetic ketoacidosis is a potentially life-threatening complication in patients with diabetes mellitus. It happens predominantly in those with type 1 diabetes, but it can occur in those with type 2 diabetes under certain circumstances...
.
Diagnosis
Ill patients may have normal to low TSH depending on the spectrum of illness. Total T4 and T3 levels may be altered by binding proteinBinding protein
A binding protein is any protein that acts as an agent to bind two or more molecules together.Examples include:*DNA-binding protein**Single-strand binding protein**Telomere-binding protein*RNA-binding protein**Poly-binding protein...
abnormalities, and medications. Reverse T3 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.