In ICD-10, the first character of each code is now alphabetic rather than numeric. This has enabled the expansion of the number of codes to provide for recently recognised conditions and more detail about common diseases.
Some diseases and groups of conditions have been moved between broad groups (ICD Chapters) to another to reflect current ideas of aetiology and pathology.
There have been several changes to the rules governing selection of the underlying cause of death. There are now only 5 rules instead of 9. The changes in the application of Rule 3 have the biggest impact.
Changes to diseases and groups of conditions to reflect current ideas of aetiology and pathology
Changes to the selection of causes of death