An understanding of the cardiovascular and respiratory systems is a critically important component of disease diagnosis and treatment. This importance is magnified by the fact that these two systems work so closely together. A variety of factors and circumstances that impact the emergence and severity of issues in one system can have a role in the performance of the other. Effective disease analysis often requires an understanding that goes beyond these systems and their capacity to work together. The impact of patient characteristics as well as racial and ethnic variables can also have an important impact.