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During aging, systolic blood pressure (Ps) continuously increases over time, whereas diastolic pressure (Pd) first increases and then slightly decreases after middle-age. These pressure changes are usually explained by changes of the arterial system alone (increase in arterial stiffness and vascular resistance). However, we hypothesize that the heart contributes to the age-related blood pressure progression as well. In this study we quantified the blood pressure changes in normal aging by using the Windkessel model for the arterial system and the time-varying elastance model for the heart, and validated the results against data from the Framingham Heart Study. Arterial changes during aging were prescribed based on literature values, whereas the cardiac changes were computed through physiological rules (compensated hypertrophy and preservation of end-diastolic volume). Results showed that, when accounting for arterial changes only, the Ps and Pd did not conform to the population data. The computed Ps changed from 100 to 122 mmHg and Pd from 76 to 55 mmHg, respectively. When taking cardiac adaptations also into account, Ps and Pd changed from 100 to 151 mmHg and 76 to 69 mmHg, respectively. Our results show that not only the arterial system, but also the heart significantly contributes to the development of blood pressure during aging. The changes in arterial properties initiate a systolic blood pressure increase, which in turn initiate a cardiac remodeling process, further contributing to the development of Ps and Pd.