Abstract
Thyroid hormone abnormalities known as nonthyroidal illness syndrome (NTIS) are characterized by a fall in serum triiodothyronine levels in total and free forms (TT3 and FT3) and an increase in the reverse form (rT3), concurrently with normal thyrotropin (TSH) levels. A more severe underlining disease can result in a decrease in serum thyroxine (T4). It occurs mainly in patients with acut…