With the demographic expansion, healthcare exigencies are increasing invariably, owing to which it is pertinent to provide healthcare services around the corner. The Internet of Medical Things (IoMT) has expedited this concept of rendering expeditious healthcare facilities to medically and geographically isolated patients. These systems empower patients and clinicians to maintain and monitor health records cost-effectively and effortlessly. This IoMT environment involves transmitting, processing, and storing sensitive patient data among the communicating entities. Evaluating and strengthening the security of such integrated and diverse healthcare networks is crucial. This research work elucidates the two most frequent and notable scenarios the first one being clinical isolation where the patient is medically advised to confine himself to healthy individuals band the second scenario is geographic isolation, where the patient is present at a remote location, spatially bound and unable to visit the doctor physically. In both scenarios, the patients are equipped with body sensors, using which the patient data is collected and further exchanged with the medical practitioner to remotely keep track of patient health. The network model for both scenarios is discussed in the upcoming section in detail. Edge and cloud servers have been used to solve latency and storage concerns. The objective of this work is to design a lightweight, mutual authentication scheme for secure data transmission and remote communication. The security strengths of the proposed JLSAIoMT: Justifiable Lightweight and Secure Mutual Authentication Scheme for Internet of Medical Things, scheme have been tested using AVISPA simulation and the RoR model. Withal, the environment of Raspbery PI has been used to analyze the execution time of the scheme. Performance parameters have also been provided using the NS2 network simulator. Moreover, the use of biometrics has also been incorporated to enhance the security of JLSAIoMT and is found to be more secure against security attacks and cost-effective compared to PSLA2P of Abdussami et al. and other counterpart schemes.