## 1 Introduction  
Technological advancements in digitalization and information exchange are driving a transformation in healthcare, mainly through patient health records (PHRs) [1, 2] and telecare medicine information systems [3], which have enhanced accessibility and convenience. Despite their benefits for diagnosis and treatment, these systems face challenges related to data accessibility, security, and interoperability [4, 5]. Concerns about data integrity, privacy, and the fragmented nature of medical records highlight the need for improved systems [6]. Blockchain technology has emerged as a potential solution [7, 8], offering a decentralized and immutable ledger that enhances security, real-time access, and interoperability across healthcare networks [9]. Blockchain addresses privacy concerns and ensures accurate treatment by giving patients more control over their data and safeguarding transactions with smart contracts [10]. Different blockchain topologies, including public, private, and consortium models, enable tailored solutions [11]. Integration with technologies like reputation systems [12], trustworthy oracles [13], proxy re-encryption [14], and the Inter Planetary File System (IPFS) [15] further enhance blockchain-based PHR systems (BPHRSs). These systems securely encrypt and store PHRs via decentralized networks, promoting privacy, data integrity, and streamlined regulatory compliance [16, 17, 18]. This ultimately improves the quality of patient care by providing a secure, transparent platform for health information management. BPHRSs that make use of Quorum [19], Ethereum [20], and Hyperledger Fabric [21] provide tamper-proof, decentralized methods for handling confidential medical records. These systems have significant limitations that prevent their general implementation in the healthcare sector despite their potential security, openness, and data integrity benefits. The high cost of establishing and maintaining blockchain infrastructure is one of its fundamental limitations [22]. Due to the intricacy of blockchain technology, many healthcare organizations may find it prohibitive to invest in the necessary infrastructure and acquire the required knowledge. The lack of established data-sharing protocols between various blockchain platforms and current healthcare systems causes interoperability problems [21]. Blockchain-based patient monitoring systems have limited potential benefits if they cannot seamlessly integrate with older systems. This can impede effective data sharing and collaboration between healthcare providers. Another issue facing BPHRS is scalability, particularly given the exponential growth in data collected on medical conditions [7]. The massive volume of data created by healthcare transactions is too much for current blockchain systems to handle, which causes delays and performance bottlenecks in data processing. The immutable nature of blockchain raises privacy concerns since it makes it difficult to remove or amend sensitive information after it has been entered into the ledger, even as it ensures data integrity [19]. Privacy concerns are brought up by this lack of flexibility, especially in light of the right to be forgotten and the need to abide by laws like the General Data Protection Regulation (GDPR) [23]. Moreover, the blockchain's data ownership presents difficulties in preserving privacy and control over medical records [20; 24]. Patients may not have precise control over their data, which could be dispersed across several networks and systems, compromising their right to privacy and making it more difficult for them to receive the appropriate care. This research addresses critical gaps in existing blockchain-based personal health record systems (BPHRS) by proposing PHR-NFT. This novel solution leverages NFTs and Hyperledger Fabric to enhance healthcare data management's security, privacy, and interoperability.