The document describes efforts to enhance the Human Phenotype Ontology (HPO) by adding layperson synonyms to make it more useful and accessible for patients. The workflow involved systematically reviewing over 12,000 HPO classes, searching external sources to identify potential layperson synonyms, assigning the synonyms and validating their use, and integrating the new synonyms into the HPO ontology. As a result, 44% of existing HPO synonyms are now classified as layperson terms, increasing the usability and interoperability of HPO for patients, clinicians and researchers.