It is well known that shape and function of heart and blood vessels are influenced by blood flow and pressure. The heart muscle grows to cope with the demands of a sportsman, the inner diameter of vessels increases with increased shear stress from blood flow, and vessel walls themselves get thicker with elevated blood pressure. Such effects are observed in healthy people with varying activity levels, and also in patients with different malfunctions. Modelling and simulating the function and the adaptation of heart and blood vessels to mechanical load is needed to fully understand the complex relations involved. A thorough understanding of these mechanisms is fundamental for good patient diagnosis and treatment planning. Also, simulations will reduce the need for time consuming and stressful invasive measurements. In this brief review, we present some of the relevant biology, and address important modelling approaches of cardiovascular functioning and adaptation.