Cardiovascular Diseases (CVDs) are common, but in many cases can be avoided. Atherosclerosis and venous thrombosis are the two major manifestations of CVD. Both are caused by complex interactions of environmental and genetic parameters. An unhealthy lifestyle in combination with certain genetic variants can contribute to atherosclerosis. Relevant genes include those involved in endothelial dysfunction, hyperlipidemia, hypertension, and inflammation. A combination of adverse influences (female hormone intake, immobilization, surgery or cancer) and variations in genes responsible for the coagulation system can also lead to thrombosis. Testing for genetic variations and adequate prophylaxis contributes to lower CVD risks.