FHIR-Specific Terms
This glossary provides definitions for key FHIR terminology that Java developers will encounter when building healthcare applications.
Core FHIR Concepts
| Term | Definition |
|---|---|
| Bundle | A container resource that groups multiple resources together for transaction, messaging, or search results |
| Capability Statement | A resource that describes the capabilities of a FHIR server (formerly called Conformance) |
| Coding | A representation of a defined concept using a symbol from a defined code system |
| CodeableConcept | A value that can be represented by one or more codes from different code systems |
| Compartment | A logical grouping of resources based on their relationship to a specific resource (e.g., Patient compartment) |
| Composition | A set of healthcare-related information assembled together into a single logical document |
| Conformance | The degree to which an implementation adheres to FHIR specifications |
| Extension | A mechanism to add additional data elements to resources beyond the base specification |
| FHIR | Fast Healthcare Interoperability Resources - the HL7 standard for healthcare data exchange |
| FHIRPath | A path-based navigation and extraction language for FHIR resources |
| Identifier | A unique identifier for a resource instance across systems |
| Modifier Extension | An extension that changes the meaning of the element it extends (must be understood) |
| Must Support | Elements that implementations must support according to a profile |
| Narrative | Human-readable summary of a resource in XHTML format |
| Operation | Server-defined functionality beyond the RESTful API (denoted with $) |
| Profile | A set of constraints on a resource or datatype |
| Provenance | A resource tracking the history, source, and reliability of resource information |
| Reference | A link from one resource to another |
| Resource | The basic unit of information exchange in FHIR (Patient, Observation, etc.) |
| REST | Representational State Transfer - the architectural style used by FHIR |
| SMART on FHIR | Standard for app authorization and launch contexts |
| StructureDefinition | A resource that defines constraints and extensions on FHIR resources |
| Terminology Service | A service that provides access to code systems, value sets, and concept maps |
| ValueSet | A set of coded values from one or more code systems |
Detailed Term Definitions
Bundle
A container resource that groups multiple resources together for transaction, messaging, or search results. Bundle types include: document, message, transaction, transaction-response, batch, batch-response, history, searchset, and collection.
Capability Statement
A resource that describes the capabilities of a FHIR server (formerly called Conformance). It declares supported resources, operations, search parameters, and security mechanisms.
Coding
A representation of a defined concept using a symbol from a defined code system. Consists of system (URI), code, and display text.
CodeableConcept
A value that can be represented by one or more codes from different code systems. Commonly used for clinical concepts that may have multiple valid representations.
Compartment
A logical grouping of resources based on their relationship to a specific resource. For example, the Patient compartment includes all resources that belong to or are about a patient (Observations, Conditions, etc.).
Composition
A set of healthcare-related information assembled together into a single logical document. Compositions are used to create clinical documents like discharge summaries.
Conformance
The degree to which an implementation adheres to FHIR specifications. Conformance resources (StructureDefinition, CapabilityStatement) define these requirements.
Extension
A mechanism to add additional data elements to resources beyond the base specification. Extensions use URLs to identify their meaning and can contain various data types.
FHIR
Fast Healthcare Interoperability Resources - the HL7 standard for healthcare data exchange. FHIR uses modern web standards (REST, JSON, XML) to enable interoperability.
FHIRPath
A path-based navigation and extraction language for FHIR resources. Similar to XPath but designed specifically for FHIR data structures.
Identifier
A unique identifier for a resource instance across systems. Identifiers consist of a system (namespace) and value, and can represent MRNs, SSNs, or other identifiers.
Modifier Extension
An extension that changes the meaning of the element it extends and must be understood by systems processing the data. Modifier extensions are distinguished from regular extensions.
Must Support
Elements that implementations must support according to a profile. Must support definitions vary by implementation guide but typically mean the element must be handled.
Narrative
Human-readable summary of a resource in XHTML format. The text element provides a renderable representation for human review.
Operation
Server-defined functionality beyond the RESTful API, denoted with $ prefix. Examples include $everything, $validate, $expand, and $translate.
Profile
A set of constraints on a resource or datatype. Profiles are defined using StructureDefinition resources and customize resources for specific use cases.
Provenance
A resource tracking the history, source, and reliability of resource information. Used for audit trails and data lineage.
Reference
A link from one resource to another. References can be literal (containing the resource ID) or logical (containing an identifier).
Resource
The basic unit of information exchange in FHIR. Resources represent healthcare concepts like Patient, Observation, Medication, and Encounter.
REST
Representational State Transfer - the architectural style used by FHIR for its API. FHIR uses standard HTTP methods (GET, POST, PUT, DELETE) for operations.
SMART on FHIR
Substitutable Medical Applications, Reusable Technologies - a standard for app authorization and launch contexts built on OAuth 2.0.
StructureDefinition
A resource that defines constraints and extensions on FHIR resources. Used to create profiles and implementation guides.
Terminology Service
A service that provides access to code systems, value sets, and concept maps. Supports operations like $validate-code and $expand.
ValueSet
A set of coded values from one or more code systems. Used to define allowed values for coded elements.
Technical Terms
| Term | Definition |
|---|---|
| HAPI | HL7 Application Programming Interface - the Java library for FHIR |
| LOINC | Logical Observation Identifiers Names and Codes - standard for lab and clinical observations |
| NDJSON | Newline Delimited JSON - format for bulk data operations |
| OAuth 2.0 | Authorization framework used for FHIR security |
| RxNorm | Standardized nomenclature for medications |
| SNOMED CT | Systematized Nomenclature of Medicine - Clinical Terms |
| UCUM | Unified Code for Units of Measure |
| US Core | FHIR implementation guide for US healthcare data exchange |
HAPI
HL7 Application Programming Interface - the Java library for FHIR. HAPI FHIR provides complete implementations for parsing, validation, and client/server operations.
LOINC
Logical Observation Identifiers Names and Codes - the standard coding system for laboratory and clinical observations. Used extensively for lab results and vital signs.
NDJSON
Newline Delimited JSON - a format where each line is a complete JSON object. Used in FHIR bulk data operations for efficient streaming.
OAuth 2.0
Open Authorization framework used for FHIR security. Provides token-based access control for FHIR APIs.
RxNorm
Standardized nomenclature for medications in the US. Provides normalized names and codes for clinical drugs.
SNOMED CT
Systematized Nomenclature of Medicine - Clinical Terms. A comprehensive clinical terminology used for encoding clinical information.
UCUM
Unified Code for Units of Measure - the standard for representing measurement units in FHIR Quantity values.
US Core
FHIR implementation guide for US healthcare data exchange. Defines profiles and requirements for US-specific use cases.
FHIR Resource Types Quick Reference
Foundation Resources
| Resource | Purpose |
|---|---|
| Bundle | Container for collections of resources |
| CapabilityStatement | Server capabilities declaration |
| OperationDefinition | Custom operation definition |
| StructureDefinition | Resource/datatype constraints |
| ValueSet | Code value sets |
| CodeSystem | Code system definitions |
| ConceptMap | Mappings between code systems |
Clinical Resources
| Resource | Purpose |
|---|---|
| Patient | Demographics and administrative information |
| Practitioner | Healthcare provider information |
| Organization | Healthcare organization |
| Encounter | Healthcare interaction/visit |
| Condition | Diagnoses and problems |
| Observation | Measurements and findings |
| Procedure | Healthcare procedures performed |
| MedicationRequest | Medication prescriptions |
| Medication | Medication information |
| AllergyIntolerance | Allergies and intolerances |
| Immunization | Immunization records |
| DiagnosticReport | Diagnostic study results |
Administrative Resources
| Resource | Purpose |
|---|---|
| Coverage | Insurance coverage |
| Claim | Healthcare claims |
| ExplanationOfBenefit | Claims adjudication details |
| Appointment | Scheduled appointments |
| Schedule | Provider availability |
| Slot | Available appointment times |
| Location | Physical place |
Infrastructure Resources
| Resource | Purpose |
|---|---|
| Bundle | Collection of resources |
| OperationOutcome | Outcome of an operation |
| Subscription | Event notification subscription |
| Parameters | Operation parameters |
Common FHIR Operations
| Operation | Scope | Description |
|---|---|---|
$everything | Patient, Encounter | Returns all resources in a compartment |
$validate | Any resource | Validates a resource against profiles |
$meta | Any resource | Returns metadata about a resource |
$expand | ValueSet | Expands a ValueSet to list all codes |
$lookup | CodeSystem | Looks up a code in a code system |
$translate | ConceptMap | Translates a code between systems |
$match | Patient | Matches patients based on criteria |
$export | System, Group, Patient | Bulk data export (Bulk FHIR) |
$document | Composition | Generates a document bundle |
$process-message | MessageHeader | Processes FHIR messages |
Code Systems Reference
Common Code System URIs
| Code System | URI | Purpose |
|---|---|---|
| LOINC | http://loinc.org | Lab and clinical observations |
| SNOMED CT | http://snomed.info/sct | Clinical terminology |
| ICD-10-CM | http://hl7.org/fhir/sid/icd-10-cm | Diagnosis codes (US) |
| CPT | http://www.ama-assn.org/go/cpt | Procedure codes |
| RxNorm | http://www.nlm.nih.gov/research/umls/rxnorm | Medications |
| UCUM | http://unitsofmeasure.org | Units of measure |
| CVX | http://hl7.org/fhir/sid/cvx | Vaccine codes |
| NDC | http://hl7.org/fhir/sid/ndc | National Drug Code |
HL7 Terminology Code Systems
| Code System | URI | Purpose |
|---|---|---|
| Administrative Gender | http://hl7.org/fhir/administrative-gender | Patient gender |
| Marital Status | http://terminology.hl7.org/CodeSystem/v3-MaritalStatus | Marital status codes |
| Contact Relationship | http://terminology.hl7.org/CodeSystem/v2-0131 | Contact relationship types |
| Observation Category | http://terminology.hl7.org/CodeSystem/observation-category | Observation categories |
| Condition Clinical | http://terminology.hl7.org/CodeSystem/condition-clinical | Condition clinical status |
| Condition Verification | http://terminology.hl7.org/CodeSystem/condition-ver-status | Condition verification status |
Common LOINC Codes for Vital Signs
| Vital Sign | LOINC Code | Display |
|---|---|---|
| Blood Pressure Panel | 85354-9 | Blood pressure panel |
| Systolic BP | 8480-6 | Systolic blood pressure |
| Diastolic BP | 8462-4 | Diastolic blood pressure |
| Heart Rate | 8867-4 | Heart rate |
| Respiratory Rate | 9279-1 | Respiratory rate |
| Body Temperature | 8310-5 | Body temperature |
| Oxygen Saturation | 2708-6 | Oxygen saturation |
| Body Weight | 29463-7 | Body weight |
| Body Height | 8302-2 | Body height |
| BMI | 39156-5 | Body mass index |
HTTP Status Codes in FHIR
| Status Code | Meaning | When Used |
|---|---|---|
| 200 OK | Success | Read, search, update operations |
| 201 Created | Resource created | Create operations |
| 204 No Content | Success, no content | Delete operations |
| 304 Not Modified | Conditional read unchanged | Conditional reads |
| 400 Bad Request | Invalid request | Malformed requests |
| 401 Unauthorized | Authentication required | Missing/invalid credentials |
| 403 Forbidden | Access denied | Insufficient permissions |
| 404 Not Found | Resource not found | Invalid resource ID |
| 409 Conflict | Version conflict | Concurrent update conflict |
| 410 Gone | Resource deleted | Accessing deleted resource |
| 412 Precondition Failed | Conditional failed | Conditional update/delete |
| 422 Unprocessable Entity | Validation failed | Business rule violations |
Search Parameter Prefixes
| Prefix | Meaning | Example |
|---|---|---|
eq | Equal (default) | date=eq2024-01-01 |
ne | Not equal | status=ne:active |
gt | Greater than | date=gt2024-01-01 |
lt | Less than | date=lt2024-01-01 |
ge | Greater or equal | date=ge2024-01-01 |
le | Less or equal | date=le2024-01-01 |
sa | Starts after | date=sa2024-01-01 |
eb | Ends before | date=eb2024-01-01 |
ap | Approximately | date=ap2024-01-01 |
Search Parameter Modifiers
| Modifier | Applies To | Description |
|---|---|---|
:exact | String | Exact match (case-sensitive) |
:contains | String | Contains substring |
:text | Token | Text search on display |
:not | Token | Negation |
:above | Token | Hierarchical above |
:below | Token | Hierarchical below |
:in | Token | In value set |
:not-in | Token | Not in value set |
:missing | Any | Element missing |
:identifier | Reference | Search by identifier |
FHIR Version History
| Version | Status | Release Date | Key Features |
|---|---|---|---|
| DSTU1 | Deprecated | September 2013 | Initial release |
| DSTU2 | Legacy | October 2015 | First widely adopted version |
| STU3 | Legacy | March 2017 | Improved resources, US Core |
| R4 | Normative | December 2019 | First normative release |
| R4B | Normative | May 2022 | Minor updates to R4 |
| R5 | Current | March 2023 | Subscriptions, SubscriptionTopic |
Tutorial Summary
This comprehensive tutorial has covered HL7 FHIR from foundational concepts through advanced implementation patterns using Java, HAPI FHIR, and Apache Camel. You should now be equipped to:
- Understand FHIR architecture and how it differs from legacy standards
- Create and manipulate FHIR resources programmatically
- Implement RESTful operations for healthcare data exchange
- Build integration workflows using Apache Camel
- Secure FHIR endpoints with modern authentication/authorization
- Validate resources against profiles and business rules
- Handle bulk data operations efficiently
- Test and monitor FHIR implementations
- Apply best practices for production systems
Additional Resources
Official Documentation
- HL7 FHIR Specification: https://www.hl7.org/fhir/
- HAPI FHIR: https://hapifhir.io/
- Apache Camel FHIR Component: https://camel.apache.org/components/latest/fhir-component.html
- SMART on FHIR: https://docs.smarthealthit.org/
- FHIR Profiling: http://hl7.org/fhir/profiling.html
Implementation Guides
- US Core Implementation Guide: http://hl7.org/fhir/us/core/
- International Patient Summary: http://hl7.org/fhir/uv/ips/
- Bulk Data Access (Flat FHIR): http://hl7.org/fhir/uv/bulkdata/
Community Resources
- FHIR Community Chat: https://chat.fhir.org/
- FHIR DevDays: https://www.devdays.com/
- Public FHIR Test Servers: http://hl7.org/fhir/test-servers.html
Version Information
- FHIR Versions Covered: DSTU2, STU3, R4, R4B, R5
- HAPI FHIR Version: 6.10.0
- Apache Camel Version: 4.0.3
Test Your Knowledge
Ready to put your learning to the test? Take our comprehensive quizzes to reinforce what you’ve learned:
- HL7 Quiz - Test your knowledge of HL7 standards including FHIR
- Health Informatics & Standards Quiz - Comprehensive quiz on healthcare interoperability standards
Related Articles
Continue your FHIR learning journey with these resources:
- Basics of FHIR - Comprehensive FHIR overview
- HL7 v2 Explained: The Messaging Standard Still Running Every Hospital in 2026 - Understanding FHIR’s predecessor
- Introduction to HL7 V3 Standard - HL7 V3 and CDA background
- Overview of IHE - Integration profiles that use FHIR
- Coded Vocabularies in Health Informatics - Understanding SNOMED, LOINC, ICD
Related Tutorials
- HL7 V2 Tutorial - Learn the legacy HL7 V2 standard
- DICOM Tutorial - Medical imaging integration with FHIR