Abstract The high rate of healthcare digitalization and the extensive use of electronic healthcare records (EHRs) have heightened the issues of data privacy, interoperability, and the ability of the system to scale. Blockchain has emerged as a promising paradigm of decentralizing trust and improving security in healthcare information systems, and its real implementation is still divided. The paper highlights a systematic review of 94 peer-reviewed articles published in the years 2019–2025, which investigate architectural designs, privacy designs, scalability designs, federated learning designs, cross-chain interoperability designs, and novel cryptography designs in health care blockchain systems. The review contributes to the research in two ways: (i) a full taxonomy of blockchain design methods of healthcare applications and (ii) an organized discussion of the gaps in the research and future trends. The results demonstrate that hybrid constructions of lightweight zero-knowledge proofs, federated learning, adaptive consensus mechanisms, and cross-chain frameworks have better potential in privacy, scalability, and regulatory compliance than blockchain-based EHR solutions.
Singh et al. (Mon,) studied this question.