Big data refers to a very large and diverse set of data that grow at exponential rates. In the modern healthcare system, medical big data face many security issues due to the presence of hackers and malicious users. Nowadays, medical big data are tremendously benefitted by Blockchain technology due to its several features, namely decentralization, confidentiality, security, privacy, etc. Nevertheless, the conventional cloud and client-server-based information storage models in healthcare are suffering from single-point failure, centralized control of data resources and privacy leakage. This paper explores the usages of Blockchain technology to manage the healthcare system by providing a solution to these problems. Here, a distributed scheme is proposed for data management, which is used to implement Blockchain technology in the healthcare sector. The proposed scheme ensures security by specifying rules with a smart contract. Results and discussions show that the proposed scheme is more efficient than the existing schemes.