Power electronics plays a crucial role in modern medical applications by providing efficient power management, conversion, and regulation across a wide range of devices. In high-power systems, such as medical imaging equipment, power electronics ensure precise control, stable operation, and optimal performance, which are essential for accurate diagnostic imaging. On the other hand, in low-power devices such as wearable health monitors and implantable medical devices, power electronics focus on enhancing energy efficiency and miniaturization. This is vital for extending battery life, reducing the need for frequent recharging or replacement, and improving patient comfort and mobility. Power electronics has therefore played a key role in enabling stable performance in critical life-support systems, therapeutic devices, as well as portable health monitors and this review discusses the role of power electronics in these various domains. Understanding these key technologies and power management integrated circuits help to improve the efficiency, reliability, and longevity of medical device. The review also identifies systemic issues such as miniaturization, energy efficiency and regulatory compliance that must be overcomes to achieve these end-goals. It also covers future trends in advanced materials for semiconductors, energy harvesting evolution, and wireless platforms. These innovations are poised to transform the industry, powering the next generation of hardware, and influencing the future of medical devices.