Personalized medicine is a medical model to health care based on their predicted response to disease or risk factors of an individual to prescribe most effective treatments and preventive measures by analyzing unique genetic makeup, lifestyle, and environmental factors. This advanced medical model leverages technologies like imaging, data analytics, and artificial intelligence to optimize diagnosis, treatment plans, and overall patient outcomes. Nanosensors are diminutive devices, operating at the nanoscale, evaluate physical, chemical, or biological stimuli, enabling early disease detection, detect environmental contaminants, help to release drugs to kill bacteria, or reduce scar-tissue growth and real-time monitoring in healthcare system. Different types of nanosensors are used in precision medicine with their different mechanisms, viz. optical, electrochemical, magnetic, and mechanical nanosensors with each offer unique advantages. Optical nanosensors leverage light-based mechanisms for biomarker detection, while electrochemical sensors excel in glucose monitoring and neurotransmitter analysis. Magnetic nanosensors find applications in magnetic resonance imaging (MRI) and carrier systems for drug delivery. Mechanical nanosensors, sensitive to physical changes, are employed in glucose monitoring, intracranial pressure detection, and muscle activity analysis. These sensors, integrated into wearable and implantable devices, transform health care by providing constant, personalized health monitoring and enabling proactive interventions, but biocompatibility and long-term stability are the challenges of these devices. However, the personalized medicine itself provides customized treatments but faces obstacles like genetic discrimination, data security concerns, and expensive costs. Key challenges include ensuring patients understand the implications, making treatments accessible to all, and managing the technical complexities involved. Addressing these through ethical guidelines, patient education, and strong infrastructure is essential for success.