What a blockchain would do here

Someone living with type 1 diabetes produces data every day. The sensor and the pump supply glucose values and insulin doses, and clinic results are added to that. These data usually sit in separate systems run by manufacturers and hospitals. Sharing them selectively with your own diabetes team is still cumbersome.

Under the heading Web3, decentralised approaches are discussed for this. The health data themselves would stay in protected systems. A blockchain would only record who received which access rights, and when those rights changed. Researchers could ask for access limited to a stated purpose. Networks such as Polkadot, which connect different blockchains, are mentioned as possible infrastructure.

Evidence thin

The evidence is thin. A 2024 systematic review in the journal of the American Medical Informatics Association found eleven biomedical blockchain applications that had been implemented and evaluated quantitatively. Only one was in use at a healthcare organisation. A 2026 review in BMC Medical Informatics and Decision Making included sixteen empirical studies of patient records, mostly prototypes and pilots. The authors report limits of scale, and conflicts with data-protection law, including the tension between the GDPR right to erasure and an immutable ledger. For the data to be usable in medicine, shared standards such as HL7 FHIR are also needed. And withdrawing consent does not retrieve data that have already been shared.

What the EU and Switzerland are doing without a blockchain

The EU is pursuing similar aims without a blockchain. The European Health Data Space has been in force since March 2025. From March 2029, patient summaries and e-prescriptions are meant to be exchangeable across the EU. Patients should be able to restrict access and see who retrieved their data. In Germany, practices and hospitals have had to use the electronic patient record since October 2025. Switzerland intends to replace the current electronic patient dossier with an electronic health dossier. According to the federal government, that is 2030 at the earliest.