The prevalence, awareness, treatment, and control of hypertension in the United States are analyzed using the National Health and Nutrition Examination Survey (NHANES) database covering the period 1988-2002. Mean body mass index was 26.1+/-0.1 kg/m2 in 1988-1991 and 27.9+/-0.2 kg/m2 in 2001-2002 (p < 0.001). In the same period, the prevalence of diabetes mellitus increased from 5.0% to 6.5% (p = 0.03). Diastolic blood pressure was 73.3+/-0.2 mm Hg in 1988-1991 and 71.6+/-0.4 mm Hg in 2001-2002 (p < 0.001). Among the 18-39 years and 60 years and older age groups, the prevalence of hypertension increased significantly since 1988-1991. Multiple regression shows age, body mass index, and being non-Hispanic black were significantly associated with hypertension. In the period 1988-2002, the percentage receiving treatment and the percentage with blood pressure controlled increased significantly. In 2001-2002, significantly more people with hypertension and diabetes reached a blood pressure target of <130/85 mm Hg. Overall, the control rates were low, especially among middle-aged Mexican-American men (8%).