Roosevelt's complex health problems offer the opportunity for two interesting comparisons of the impact of physical illness on political decision making. Roosevelt suffered from at least two major kinds of debilitating illness: polio and cardiovascular disease. The first, which paralyzed Roosevelt beginning in 1921, appeared to exert little, if any, impact on his decision-making skills and abilities. The second, consisting of congestive heart failure, hypertension, and hypertensive heart disease, seems to have exerted subtle, increasing, but typically transient effects on his cognitive skills and abilities over time. These effects began to exert some influence over his decision-making abilities beginning by late 1943.

Importantly, the impact of Roosevelt's health on his decision-making capacities proved inconsistent over time, in keeping with the nature of his ailment. In the majority of cases, including the conference at Yalta, where the effect of Roosevelt's health on his abilities has been most consistently scrutinized and criticized, Roosevelt's illness probably played no part in the outcomes he achieved. However, it appears likely that the increasing severity of Roosevelt's cardiovascular disease exerted some subtle, albeit profound, negative impacts on his judgments and behaviors at some earlier meetings and conferences. Specifically, Roosevelt's choice between General MacArthur's and Admiral Nimitz's plans concerning the future of the Pacific campaign, made in July 1944 in Hawaii, seemed affected, at least in part, by his decreasing energy, increasing detachment, and shortened attention span.