A blockchain-based system for patient data privacy and security addresses the challenges of ensuring privacy and security in wireless body sensor networks (WBSNs) integrated with cloud computing. Traditional sensor-cloud infrastructure (S-CI) relies on a single trusted authority, which is insufficient for managing access control, privacy, data confidentiality, and authorization rights. Blockchain technology offers a promising solution due to its decentralized and tamper-resistant nature. This study proposes a Blockchain-Based Access Control Model (BBACM) to enhance privacy and security of patient data. The model is designed to manage access to both patient physiological parameters (PPPs) and personal health information (PHI). A real-world scenario involving a paralysis patient was implemented to validate the model. Experimental results show that BBACM significantly improves fine-grained access control, security, privacy, scalability, and availability of PHI. The system leverages blockchain's decentralized nature to address the challenges of S-CI, providing a robust framework for secure and privacy-preserving healthcare data management. Blockchain technology is also noted for its ability to ensure trust, transparency, and accountability, making it suitable for healthcare applications. The integration of blockchain with WBSNs and cloud computing can lead to significant reforms in healthcare by improving data access, enabling device tracking, and ensuring data confidentiality. However, there are still challenges to be addressed in the integration of blockchain with current electronic health record systems. The study highlights the potential of blockchain technology in enhancing the security and privacy of patient data in healthcare.A blockchain-based system for patient data privacy and security addresses the challenges of ensuring privacy and security in wireless body sensor networks (WBSNs) integrated with cloud computing. Traditional sensor-cloud infrastructure (S-CI) relies on a single trusted authority, which is insufficient for managing access control, privacy, data confidentiality, and authorization rights. Blockchain technology offers a promising solution due to its decentralized and tamper-resistant nature. This study proposes a Blockchain-Based Access Control Model (BBACM) to enhance privacy and security of patient data. The model is designed to manage access to both patient physiological parameters (PPPs) and personal health information (PHI). A real-world scenario involving a paralysis patient was implemented to validate the model. Experimental results show that BBACM significantly improves fine-grained access control, security, privacy, scalability, and availability of PHI. The system leverages blockchain's decentralized nature to address the challenges of S-CI, providing a robust framework for secure and privacy-preserving healthcare data management. Blockchain technology is also noted for its ability to ensure trust, transparency, and accountability, making it suitable for healthcare applications. The integration of blockchain with WBSNs and cloud computing can lead to significant reforms in healthcare by improving data access, enabling device tracking, and ensuring data confidentiality. However, there are still challenges to be addressed in the integration of blockchain with current electronic health record systems. The study highlights the potential of blockchain technology in enhancing the security and privacy of patient data in healthcare.