Ji Hyun Kim, Aram Yang, Inhyuk Jung, Yonghee Hong, Eungu Kang, Jisun Park, Kyungchul Song, Junghwan Suh, Jungmin Ahn, Eun Byoul Lee, Hyejin Lee, Minji Lim, Soyoon Jung, Wonkyung Jo, Younglim Shin, Eun-Gyong Yoo, Young-Jun Rhie, Jin Ho Choi, Jieun Lee
Congenital hypothyroidism remains one of the most preventable causes of neurodevelopmental impairment. Population-based newborn screening has substantially improved outcomes; however, optimal practice requires appropriate timing of screening, special attention to high-risk subgroups, prompt initiation of levothyroxine, and structured long-term follow-up including re-evaluation for transient disease, transition to adult care, genetic evaluation, and monitoring of neurodevelopment and health-related quality of life. This review summarizes the 2025 Korean clinical practice guideline in 10 key questions and 28 recommendations, integrating international consensus recommendations and the latest domestic evidence across five domains: newborn screening, diagnostic evaluation, levothyroxine treatment, monitoring, and re-evaluation/transition with long-term follow-up.