Healthcare is increasingly becoming a data-intensive field in which electronic health records, medical imaging, laboratory measurements, wearable sensors and molecular information are collected across a patient's lifetime. Digital twin technology offers a way to combine these heterogeneous data into a continuously updated computational representation of a patient, organ, device or healthcare process. Unlike a static medical record or an isolated computer simulation, a healthcare digital twin is intended to represent relevant characteristics of a physical counterpart and support monitoring, prediction, simulation and decision-making. Recent research shows that healthcare digital twins can be developed at different scales, ranging from individual organs such as the heart to patient-level models and hospital operations. Artificial intelligence, mechanistic modelling, Internet of Things devices, cloud and edge computing, medical imaging and multi-omics data can contribute to the construction and updating of a twin. Such systems may support personalized treatment planning, early detection of deterioration, surgical planning, clinical trial design, drug response prediction and optimization of hospital workflows. This paper reviews the concept, architecture, enabling technologies, applications and limitations of digital twins in healthcare. Particular attention is given to data integration, model validation, interoperability, privacy, cybersecurity and ethical responsibility. Although digital twins have substantial potential for precision healthcare, a complete whole-body twin remains a research objective rather than a routine clinical product. Their safe adoption will depend on reliable data, validated models, explainable decision support, strong governance and meaningful participation of clinicians and patients.

Shifana Sagar, Ms.Riya K Prakash, Dr. L C Manikandan, "Digital Twin in Healthcare" International Journal of Scientific Research and Engineering Development, V9(5): Page(567-573) September - October 2026. ISSN: 2581-7175. www.ijsred.com. Published by Scientific and Academic Research Publishing.