Cardiovascular diseases (CVDs) are the leading cause of mortality in the world (32.9%) as well as in India (27.4%). Blood flow accompanied by clot formation (or coagulation) and clot lysis (or fibrinolysis) is the phenomenon that underlies CVDs. It is important to understand the rheology of blood and clots and the biochemistry of coagulation, as well as the mechanics of blood vessels, when trying to capture the phenomenon using mechanistic models. Rheological models of blood can be used to simulate blood flow, whereas Mathematical models of coagulation can be used to test hypotheses about clotting mechanisms. In this talk, the ability of model simulations to interpret laboratory data for coagulation as well as for the diagnosis of CVD s, in particular atherosclerosis will be examined and demonstrated. The advantages of this approach will be highlighted.