The document summarizes guidelines for diagnosing inborn errors of metabolism (IEM) presenting in neonates from AIIMS, Delhi. It outlines key clinical pointers towards IEM like family history or consanguinity. Initial investigations should include blood gases, glucose, ammonia and lactate levels. Based on results, IEM can be categorized as urea cycle defects, organic acidemias or others. Confirmatory tests include urine organic acids analysis, plasma amino acids and acylcarnitine profiles. Prompt diagnosis and management is important as outcomes depend on rapid detection and treatment of underlying causes like hyperammonemia.