CVD risk factors affect BP through over activation of the renin-angiotensin-aldosterone system, activation of the sympathetic nervous system, inhibition of the cardiac natri- uretic peptide system, endothelial dysfunction, and other Treating some of the other modifi- able risk factors may reduce BP through modification of shared pathology, and CVD risk may be reduced by treating global risk factor burden. Recommendation-Specific Supportive Text 1. Observational studies have demonstrated that CVD risk factors frequently occur in combination, with 3 risk factors present in 17% of patients.S2.4-1 A meta-analysis from 18 cohort studies involving 257384 patients identi- fied a lifetime risk of CVD death, nonfatal MI, and fatal or nonfatal stroke that was substantially higher in adults with 2 CVD risk factors than in those with only 1 risk 3. Classification of BP 3.1. Definition of High BP Recommendation for Definition of High BP References that support the recommendation are summarized in Online Data Supplement 2. COR LOE Recommendation I B-NR 1. BP should be categorized as normal, elevated, or stage 1 or 2 hypertension to prevent and treat high BP (Table 6).S3.1-1 S3.1-20 Synopsis Although a continuous association exists between higher BP and increased CVD risk (see Section 2.1), it is useful to categorize BP levels for clinical and public health decision making. In the present document, BP is categorized into 4 levels on the basis of average BP measured in a healthcare setting (office pressures): normal, elevated, and stage 1 or 2 hypertension (Table 6). Online Data Supplement C illustrates schematically the SBP and DBP categories defining normal BP, elevated BP, and stages 1 and 2 hypertension. 