HL7 Version 2

  • Tim Benson
  • Grahame Grieve
Part of the Health Information Technology Standards book series (HITS)


Hl7 v2 is the most widely used healthcare interchange format. Messages are sent in response to trigger events. Messages comprise a set of segments, defined using an abstract message syntax table. Segments contain fields and fields contain components; components may contain sub-components, which are separated by delimiters. Segments are specified in segment definition tables. Z-segments are locally defined. Data types are the basic building blocks in each element. Some are simple, others are complex. Codes are defined using tables.


HL7 v2 Trigger event Segment Abstract message syntax table Field Component Sub-component Data type Delimiter Message header (MSH) Event type (EVN) Patient identification details (PID) Patient visit (PV1) Request and specimen details (OBR) Result details (OBX) Z-segment Coded no exceptions (CNE) Coded with exceptions (CWE) HL7 tables 


  1. 1.
    Health Level Seven Standard Version 2.8.2 – an application protocol for electronic data exchange in healthcare environments. ANSI/HL7 V2.8.2-2015.Google Scholar

Further Reading

  1. The following books only cover HL7 v2.Google Scholar
  2. Heitmann K, Bloebel B, Dudeck J. HL7 communication standard in medicine, short introduction and information. Cologne: Verlag Alexander Mönch; 1999.Google Scholar
  3. Henderson M. HL7 messaging, version 2, vol. 2. Aubrey: O’Tech Inc; 2007.Google Scholar
  4. Bhagat R, Hui C. HL7 for busy professionals: your no sweat guide to understanding HL7. Anchiove. 2015.Google Scholar

Copyright information

© Springer-Verlag London 2016

Open Access This chapter is licensed under the terms of the Creative Commons Attribution-NonCommercial 2.5 International License (, which permits any noncommercial use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

Authors and Affiliations

  • Tim Benson
    • 1
  • Grahame Grieve
    • 2
  1. 1.R-Outcomes LtdNewburyUK
  2. 2.Health Intersections Pty LtdMelbourneAustralia

Personalised recommendations