Table 2.

New chapters and sections in ICD-11-MMS

Title	Reason for addition
Chapter 3: Diseases of the blood or blood-forming organs Chapter 4: Diseases of the immune system	These two chapters were split from a single chapter in ICD-10, recognizing differences in etiology, manifestations, and care
Chapter 7: Sleep–wake disorders	This topic has become more prominent since the 10th revision. The chapter mostly includes new concepts with some concepts moved from other chapters in ICD-10
Chapter 17: Conditions related to sexual health	This topic has become more prominent since the 10th revision. The chapter mostly includes concepts moved from other chapters in ICD-10, combined with some new concepts
Chapter 26: Traditional medicine conditions	This entirely new supplementary chapter in ICD-11 enables coding in terms of traditional medicine concepts, where required
Extension codes section	Codes in this section can be combined with a stem code to provide additional information
Functioning section	Some national modifications of ICD-10 added sections to allow patient functioning to be recorded. ICD-11 provides a supplementary section for functioning assessment, aligned with the WHO International Classification of Functioning