WHO ICD-11 API
World Health Organization · Health
Official WHO ICD-11 classification browser and coding API. Search, browse, and linearize ICD-11 codes for mortality and morbidity statistics. Supports full hierarchy traversal, coding hints, and postcoordination.
Authentication
OAuth2
OAuth2 client credentials — register at icd.who.int/icdapi. Token endpoint: https://icdaccessmanagement.who.int/connect/token
Sample Requests
GET
Search ICD-11 codes
Search ICD-11 MMS codes by keyword
https://id.who.int/icd/release/11/mms?q=diabetes&subtreeFilterUsage=false
Hover any highlighted part to learn what it does
Headers — extra info sent with the request
| API-Version | v2 |
| Authorization | Bearer {access_token} |
| Accept-Language | en |
curl -X GET "https://id.who.int/icd/release/11/mms?q=diabetes&subtreeFilterUsage=false" \
-H "API-Version: v2" \
-H "Authorization: Bearer {access_token}" \
-H "Accept-Language: en"import requests
params = {
"q": "diabetes",
"subtreeFilterUsage": "false"
}
headers = {
"API-Version": "v2",
"Authorization": "Bearer {access_token}",
"Accept-Language": "en"
}
response = requests.get(
"https://id.who.int/icd/release/11/mms",
params=params,
headers=headers,
)
print(response.json())const url = new URL('https://id.who.int/icd/release/11/mms');
url.searchParams.set('q', 'diabetes');
url.searchParams.set('subtreeFilterUsage', 'false');
const response = await fetch(url, {
headers: {
'API-Version': 'v2',
'Authorization': 'Bearer {access_token}',
'Accept-Language': 'en'
},
});
const data = await response.json();
console.log(data);package main
import (
"fmt"
"io"
"net/http"
"net/url"
)
func main() {
baseURL, _ := url.Parse("https://id.who.int/icd/release/11/mms")
q := baseURL.Query()
q.Set("q", "diabetes")
q.Set("subtreeFilterUsage", "false")
baseURL.RawQuery = q.Encode()
targetURL := baseURL.String()
req, _ := http.NewRequest("GET", targetURL, nil)
req.Header.Set("API-Version", "v2")
req.Header.Set("Authorization", "Bearer {access_token}")
req.Header.Set("Accept-Language", "en")
client := &http.Client{}
resp, _ := client.Do(req)
defer resp.Body.Close()
body, _ := io.ReadAll(resp.Body)
fmt.Println(string(body))
}require "net/http"
require "json"
uri = URI("https://id.who.int/icd/release/11/mms")
uri.query = URI.encode_www_form({
"q" => "diabetes",
"subtreeFilterUsage" => "false"
})
http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = uri.scheme == "https"
req = Net::HTTP::Get.new(uri)
req["API-Version"] = "v2"
req["Authorization"] = "Bearer {access_token}"
req["Accept-Language"] = "en"
res = http.request(req)
puts JSON.parse(res.body)<?php
$url = "https://id.who.int/icd/release/11/mms?" . http_build_query([
"q" => "diabetes",
"subtreeFilterUsage" => "false"
]);
$opts = ["http" => [
"method" => "GET",
"header" => implode("\r\n", [
"API-Version: v2",
"Authorization: Bearer {access_token}",
"Accept-Language: en"
]),
]];
$ctx = stream_context_create($opts);
$res = file_get_contents($url, false, $ctx);
print_r(json_decode($res, true));Postman Setup Guide
- Register free at https://icd.who.int/icdapi to get client_id and client_secret
- Get a token: POST https://icdaccessmanagement.who.int/connect/token with grant_type=client_credentials
- In Postman, set Authorization header: Bearer {access_token}
- Add headers API-Version: v2 and Accept-Language: en
- GET https://id.who.int/icd/release/11/2024-01/mms/search?q=diabetes to search
What can you build with WHO ICD-11 API?
WHO ICD-11 API is a Health API. Developers commonly use health APIs for:
- accessing medical reference data and drug information
- building patient-facing health tracking apps
- integrating with EHR and telemedicine platforms
- looking up ICD codes and clinical terminology
- powering wellness and fitness applications
OAuth 2.0. OAuth lets your app act on behalf of a user. You redirect them to authorise access, receive a token, then use that token in requests. Best for accessing user-owned data. WHO ICD-11 API is free to use, making it a low-risk choice to experiment with.
New to APIs? Read our beginner's guide · Learn about API keys · What is REST?