HL7 SN Structured Numeric
HL7 datatype components SN components from HL7 v2.5.1 Hide components
These are the generated components for the version selected at the top of the page. The article stays practical, and this panel follows the chosen HL7 version.
Components
SN is a structured numeric value. It keeps comparators, ratios, ranges, and numeric modifiers separate so a result like '<5' does not get mistaken for a plain 5.
In this guide, SN appears in SAC.29, SAC.31, TCC.12, TCC.4, TCC.5, TCC.6 and related fields. That used-by list is a good reality check: the datatype is only half the story, and the field that uses it tells you the workflow.
The component panel above is expanded by default because most datatype pages are used as quick lookup pages. Start there for the exact HL7 v2.5.1 shape, then use the notes below for the practical gotchas.
SN-1 to SN-4: Component Quick Read
The generated component panel above is the formal quick lookup. The short version is below so you can scan the shape without counting carets by eye.
- SN-1 Comparator - Comparator. Type ST.
- SN-2 Num1 - Num1. Type NM.
- SN-3 Separator/Suffix - Separator/Suffix. Type ST.
- SN-4 Num2 - Num2. Type NM.
Practical Notes
Text still has to survive HL7 delimiters. If the source value can contain |, ^, ~, &, or a backslash, encode it before putting it into the message. Integration Soup and the HL7 parser helpers include HL7Encode and HL7Decode for that exact kind of cleanup.
In HL7 Soup Web, click a field that uses SN and the interpretation view will show which component you are sitting in and where that value lives in the raw message. That is especially handy with compact datatypes because one missing caret can move every value after it.
Official and Reference Notes
For formal reference, compare the generated HL7 v2.5.1 panel above with the HL7 v2.5.1 datatype list and the HL7 Terminology data type code system. Local implementation guides can narrow allowed values, tables, and component usage.