  IoT has enabled the rapid growth of smart remote healthcare applications.
These IoT-based remote healthcare applications deliver fast and preventive
medical services to patients at risk or with chronic diseases. However,
ensuring data security and patient privacy while exchanging sensitive medical
data among medical IoT devices is still a significant concern in remote
healthcare applications. Altered or corrupted medical data may cause wrong
treatment and create grave health issues for patients. Moreover, current remote
medical applications' efficiency and response time need to be addressed and
improved. Considering the need for secure and efficient patient care, this
paper proposes a lightweight Blockchain-based and Fog-enabled remote patient
monitoring system that provides a high level of security and efficient response
time. Simulation results and security analysis show that the proposed
lightweight blockchain architecture fits the resource-constrained IoT devices
well and is secure against attacks. Moreover, the augmentation of Fog computing
improved the responsiveness of the remote patient monitoring system by 40%.
