Heart failure has a growing global impact. The incidence of heart failure with preserved ejection fraction (HFpEF) in particular has been consistently increasing, and it will likely become the prevailing type of heart failure. Despite the growing predominance, less is known about the underlying mechanisms that contribute to HFpEF compared with heart failure with reduced ejection fraction (HFrEF). In fact, HFpEF appears to be the end result of a diverse group of processes. Comorbidity burden appears to play a greater role in outcomes from HFpEF than from HFrEF. The diagnosis of HFpEF is also not nearly as straightforward as that of HFrEF and relies heavily on exclusion of other possible causes of heart failure. Right heart catheterization with measurement of pressures remains the gold standard but can be impractical. Treatment options for HFpEF are limited and do not completely overlap with HFrEF. Management primarily focuses on symptom relief and comorbidity control. Unlike HFrEF, no available treatment for HFpEF has been shown to improve morbidity and mortality.