> For the complete documentation index, see [llms.txt](https://docs.snomed.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.snomed.org/education/snomed-ct-education-editorial-guide/readme/authoring/domain-specific-modeling/clinical-finding-and-disorder/clinical-finding-and-disorder-modeling/specific-clinical-finding-and-disorder-modeling/obstruction.md).
# Obstruction
**This Editorial Guide is used for Education Purposes Only. It is used in the Authoring Courses and Certifications. It is based on the January 2026 Editorial Guide.**
Since an obstruction describes blockage inside the space of a tubular structure, the Finding site of obstruction concepts should be a value from the 113342003 |Structure of lumen of body system (body structure)| subhierarchy.
For example,
When modeling gastrointestinal tract obstruction concepts, the Finding site value should be a value from the 432899004 |Structure of lumen of gastrointestinal tract (body structure)| hierarchy as the site obstructed is the lumen of the tract.
{% hint style="info" %}
At present, some but not all anatomy content exists to support this model for tracts, ducts and blood vessels beyond the gastrointestinal tract but is expected in the future.
{% endhint %}
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