Join us for the first of our series of Vascular Fundamentals podcasts. In our first episode, we will be breaking down the basics of arterial haemodynamics looking at the physiology of the circulation and how an understanding of it aids our decision making as vascular surgeons. We will attempt to explain the relationship between pressure, flow and peripheral resistance and how they are affected in vascular disease. What role does blood viscosity and Poiseuille's Law play in affecting blood flow? What actually is peripheral resistance? At what point does a stenosis become a significant stenosis and why? Some of the important questions we will explain. With Justin Woolgar and Joanna Halman.