Background: Healthcare systems generate vast amounts of sensitive patient information that require robust security mechanisms. Traditional centralized databases remain vulnerable to cyberattacks, unauthorized access, data manipulation, and interoperability challenges. Blockchain technology has emerged as a promising solution for enhancing healthcare data security through decentralization, transparency, immutability, and cryptographic protection. Objective: This study investigates the applications of blockchain technology in healthcare data security, evaluating its effectiveness in protecting patient information, improving interoperability, and strengthening trust among healthcare stakeholders. Methods: A mixed-method research approach was employed involving a systematic review of blockchain healthcare implementations and a survey of 300 healthcare professionals, IT specialists, and healthcare administrators. Quantitative and qualitative analyses were performed to evaluate perceived benefits, challenges, and future adoption potential. Results: Approximately 89.3% of respondents believed blockchain improves healthcare data security, while 84.7% reported enhanced patient data control. Key applications included electronic health record (EHR) management, medical supply chain security, patient consent management, telemedicine security, and health insurance processing. Major challenges included scalability (68.2%), implementation costs (61.4%), and regulatory concerns (57.9%). Conclusion: Blockchain technology demonstrates significant potential for improving healthcare data security, interoperability, and patient trust. Strategic implementation, regulatory frameworks, and integration with emerging technologies such as artificial intelligence may facilitate broader adoption in healthcare systems.