Why Regular Updates to ICD Matter for Global Health

Every disease, injury, or cause of death recorded anywhere in the world needs a common language to be understood globally. That language is the International Classification of Diseases (ICD), maintained by the World Health Organization. But here’s the catch: diseases evolve, science advances, and new health threats emerge. A classification system frozen in time would quickly become useless. That’s why regular revisions of the ICD are not just bureaucratic updates; they are the backbone of how the world tracks health, allocates resources, and shapes policy.

Why the ICD needs regular revisions 🔗

The ICD has been around since the late 19th century, originally designed to standardize cause-of-death reporting across countries. Over the decades, it has expanded into a comprehensive system covering injuries, mental health conditions, disorders, and even external causes of disease. Without periodic revisions, the system simply cannot keep pace with medical reality.

New diseases and emerging health threats 🔗

Consider how much has changed since ICD-10 was endorsed in 1990. We’ve lived through HIV transitioning from a death sentence to a chronic manageable condition, the global rise of antimicrobial resistance, the explosion of digital lifestyles, and a pandemic that reshaped public health forever. Each of these developments demanded new codes, new categories, and new ways of capturing data. An outdated classification means missing diseases, undercounting deaths, and misdirecting resources.

Improving the quality of health statistics 🔗

Health data is only as good as the system that classifies it. When two countries use different definitions for the same condition, comparing health trends becomes nearly impossible. Revisions correct outdated categories, refine definitions, and make data more reliable. For instance, in ICD-11, stroke has finally been reclassified as a neurological disorder rather than a circulatory one, a long-overdue change that better reflects how doctors actually treat and study the condition.

Keeping pace with technology 🔗

The earlier revisions were designed for paper-based records. Today, hospitals run on electronic health records, AI-assisted diagnosis, and cross-border data sharing. A classification system must be built to work in this environment, or it becomes a bottleneck. Revisions allow the ICD to align with modern healthcare infrastructure rather than slowing it down.

Key updates in ICD-11 🔗

The eleventh revision was adopted by the 72nd World Health Assembly in 2019 and came into effect on 1 January 2022. It took more than a decade to develop and involved more than 15,000 experts from 155 countries. The changes are not cosmetic; ICD-11 is, in many ways, a different system altogether.

A bigger, more specific code structure 🔗

ICD-10 contained around 14,000 codes. ICD-11 expanded this to roughly 17,000 unique codes underpinned by more than 120,000 codable terms. By using code combinations, more than 1.6 million clinical situations can now be captured. This means doctors and researchers can describe cases with a precision that was simply not possible before. The code structure itself has also changed: each category now features four characters before the decimal point instead of three, allowing finer subcategorisation.

Built for the digital age 🔗

One of the biggest shifts is that ICD-11 is digital-first. It comes with an online coding tool, an application programming interface (API) that allows software systems to access ICD content directly, and built-in support for multiple languages. Health information systems can integrate ICD-11 natively, which reduces errors and training costs. The 2025 update added advanced natural language processing, improved spelling correction, and expanded availability to 14 languages, with seamless interoperability with other terminologies like Orphanet and MedDRA.

New chapters and reclassified conditions 🔗

ICD-11 contains 26 chapters, five more than its predecessor. Some of the most notable additions and changes include:

Traditional medicine: For the first time, conditions diagnosed under traditional medicine systems have a place in the global classification. The 2025 update introduced a new module covering Ayurveda, Siddha, and Unani, allowing systematic tracking of conditions diagnosed under these systems alongside conventional medicine. This is a particularly significant development for countries where traditional medicine plays a major role in healthcare delivery.

Sexual health: Conditions previously scattered across other chapters, like gender incongruence, are now grouped together. Notably, gender incongruence has been moved out of the mental health chapter, reflecting current scientific understanding.

Immune system disorders: Allergies and autoimmune conditions are now grouped under a dedicated chapter, making them easier to study and track.

Gaming disorder: One of the more talked-about additions, gaming disorder has been formally recognised under addictive behaviours, defined by impaired control over gaming and continuation despite negative consequences.

Antimicrobial resistance: Codes are now aligned with the Global Antimicrobial Resistance Surveillance System (GLASS), enabling better tracking of one of the gravest public health threats of our time.

Patient safety: ICD-11 can capture data on adverse events in healthcare, helping identify unsafe workflows and reduce preventable harm.

The impact on public health 🔗

Why should any of this matter to someone outside the field of medical coding? Because the ICD shapes decisions that touch every citizen, often invisibly.

Smarter health policy and resource allocation 🔗

Governments use ICD data to decide where to build hospitals, which diseases to prioritise in national programmes, and how much funding to allocate to research. If a condition is poorly classified or underreported, it becomes invisible in policy debates. By improving precision, ICD-11 helps health ministries direct money and manpower to where they are actually needed. Updated mortality and morbidity data also feeds into international targets like the Sustainable Development Goals.

Better disease surveillance 🔗

The COVID-19 pandemic showed the world how critical real-time disease surveillance is. ICD-11 is designed for the kind of fast, interoperable data exchange that modern outbreak response requires, with its API-based design and standardised digital format. When the next pandemic comes, the ability to compare data across borders quickly will save lives.

Stronger research and clinical care 🔗

Researchers rely on classified data to study disease patterns, evaluate treatments, and develop new therapies. More specific codes mean more precise studies. Clinicians benefit too, because the new structure supports better documentation and clinical decision support tools. For health insurance and reimbursement, accurate coding affects what gets paid for and what doesn’t, with direct consequences for patients.

Inclusion of traditional medicine in India’s context 🔗

The inclusion of Ayurveda, Siddha, and Unani in ICD-11’s traditional medicine module is particularly relevant given India’s deep reliance on AYUSH systems alongside modern medicine. For the first time, the country can generate internationally comparable data on conditions treated under these systems. This opens doors for evidence-based integration of traditional and modern healthcare and gives Indian practitioners a formal voice in the global classification framework.

Challenges in adopting ICD-11 🔗

Transitioning from ICD-10 to ICD-11 is not a simple software upgrade. It requires training thousands of doctors, coders, and statisticians; updating hospital information systems; and redesigning national reporting workflows. As of May 2024, 132 Member States and areas were at various phases of implementing the new classification system, with 72 countries having commenced the implementation process. The pace varies widely. Some countries have moved quickly; others are still evaluating. The challenge is to balance the long-term benefits of better data with the short-term costs of transition. Mapping tables between ICD-10 and ICD-11 help ease this process, but a true shift requires sustained investment and political will.

Why this matters for the future of global health 🔗

Regular ICD revisions are not just about adding new codes. They are about keeping the global health information system honest, accurate, and useful. Without them, we would still be measuring 21st-century diseases with 20th-century tools. Every revision is a quiet but powerful step toward a world where decisions about health, whether in a small clinic or in a national policy meeting, are made on the best possible information.

What do you think? Should low- and middle-income countries be given more international support to accelerate their transition to ICD-11, even if it means delaying other health priorities? And how do you feel about the inclusion of conditions like gaming disorder, where the science is still evolving, in a global classification system?

References

1. https://www.who.int/standards/classifications/classification-of-diseases
2. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(19)31205-X/fulltext
3. https://www.who.int/news/item/11-02-2022-who-s-new-international-classification-of-diseases-(icd-11)-comes-into-effect
4. https://www.who.int/news/item/14-02-2025-who-releases-2025-update-to-the-international-classification-of-diseases-(icd-11)
5. https://www.who.int/news/item/18-06-2018-who-releases-new-international-classification-of-diseases-(icd-11)
6. https://www.who.int/standards/classifications/frequently-asked-questions/gaming-disorder
7. https://pmc.ncbi.nlm.nih.gov/articles/PMC8577172/