The European Health Data Space and the Secondary Use of Sensitive Health Data.
INTRODUCTION: The European Health Data Space (EHDS) is one of the European Union's most ambitious data-governance projects. It aims to create a common framework through which electronic health data can be accessed and reused across Member States for care, research, innovation, policy, and public-interest purposes. Its practical viability depends not only on digital infrastructure, but also on legal, ethical, and organisational harmonisation, particularly for genetic and genomic data. METHODS: This paper examines the EHDS with emphasis on the secondary use of health data. It reviews the EHDS institutional architecture, discusses Finland's Findata as a national model for structured access, and analyses challenges for data holders and data donors, including interoperability, governance burdens, privacy protection, residual re-identification risk, and genomic-data sensitivity. RESULTS: A cross-border cancer-genomics case study shows that the EHDS can streamline data discovery and the routing of access requests, but does not by itself eliminate legal fragmentation, heterogeneous ethics review, and consent-related barriers. DISCUSSION: Effective implementation will require harmonisation beyond infrastructure, including clearer consent standards, more consistent ethics procedures, interoperable metadata, and proportionate safeguards for genomic data.