Description: The objective of this study was to describe secular trends in the distribution of blood pressure and prevalence of hypertension in US adults and changes in rates of awareness, treatment, and control of hypertension. The study design comprised nationally representative cross-sectional surveys with both an in-person interview and a medical examination that included blood pressure measurement. Hypertension awareness, treatment, and control also have improved tremendously during the same period, accounting for much of the shift at the upper end of the distribution. Despite these favorable trends, many people with hypertension are unaware of their condition, and many more are untreated or inadequately treated.