The world's healthcare systems are experiencing major transition in access, data management, control and disease treatment. With the advancements in data capturing and connected technology the amount of healthcare data is projected approximately 2314 exabyte for year 2020[10]. The cyber criminals are putting lots of efforts, time and resources to exploit and monetize healthcare data. With this threat, the growth of cybersecurity market in healthcare industry is expected to reach USD 27.10 billion by 2026[11]. The blockchain can help in creating a single database to collect data during clinical trials and allow patients' data security. In this paper we propose a secure framework which is based on blockchain to ensure the security of healthcare data. The proposed framework considers wearable sensors, Internet of things (IoT) devices, and computational power. The framework improves the security, privacy and efficiency of the data in the conventional healthcare system.