Haptic feedback is essential for achieving virtual and augmented reality (VR/AR) systems with high fidelity and realism. Haptic-enabled VR/AR systems offer a proficient environment in which to enhance the skills of medical practitioners. While pneumatic actuation is traditionally used in heavy automation industries, haptics researchers have utilized pneumatic techniques to produce various haptic effects, i.e., stiffness feedback and contour control, and these techniques have shown promising results in the medical domain. In this paper, we focus on the use of pneumatic-actuated haptic systems in VR/AR-based medical simulators. We begin with the taxonomy of the physical-virtual continuum and discuss the role of pneumatics in medical haptic systems. Furthermore, we propose the conceptual design architecture of a pneumatic haptic system. In addition, the systematic state-of-the-art role of pneumatic haptics in medical systems is presented for different categories. In this paper, we provide a systematic review and discuss the study of pneumatics to provide guidelines for the design and development of pneumatic haptic medical systems.