Transitory neonatal hyperthyroidism

This code signifies a temporary elevation of thyroid hormone levels in a newborn, typically resolving spontaneously within weeks or months. It is a transient condition, distinct from congenital or permanent hyperthyroidism, and often results from maternal thyroid-stimulating immunoglobulin (TSI) transfer across the placenta.

Assign this code when documentation confirms a diagnosis of hyperthyroidism in a neonate that is explicitly stated as transitory or temporary. This typically occurs in infants born to mothers with Graves' disease or other autoimmune thyroid conditions. Supporting documentation would include laboratory results showing elevated thyroid hormones (T3, T4) and suppressed TSH, along with clinical signs of hyperthyroidism in the newborn, with subsequent normalization.

• Do not use this code for congenital hyperthyroidism (E03.0) or other permanent forms of thyroid dysfunction.
• Ensure the documentation clearly specifies the transitory nature of the hyperthyroidism; otherwise, a more general or permanent hyperthyroidism code may be appropriate.
• Consider sequencing this code as a secondary diagnosis if the primary reason for admission or encounter is related to another neonatal condition.