You can expand and collapse the hierarchy by clicking the triangle in front of concepts. Expanding a node reveals the children of a concept, allowing you to browse down the hierarchy. As you continue to expand the children of a concept, you will eventually reach the end of the line with a concept that doesn't have any more children. These concepts have no triangle in front of them.
The SNOMED CT hierarchical navigator visualizes the concept tree via the stated or the inferred Is a relationships.
Concept tooltips in the navigator display detailed information about the concept, including the ID, the Fully Specified Name, and the module. The number of descendants, if any, is also displayed
