Sick euthyroid syndrome Low T3 syndrome

• Facts:
  Though to be due to caloric deprivation and an increase in cytokine levels (eg. IL-1, IL-6)
• History / PE:
  Any patient with an acute, severe illness
• Diagnosis:
  MC pattern is normal TSH, T4, and low T3
• Notes:
  Decreased levels of T3 are due to the decreased peripheral conversion of T4 to T3
• Differential Diagnosis:
  Hypothyroidism