A new system is proposed for treating the spectrum of patients with high blood pressure. It is based on studies of the renin axis using renin profiling, pharmacologic probes and our bipolar vasoconstriction-volume hypothesis. The new system does not require renin profiling, pharmacologic testing or a vasoconstriction-volume analysis for widespread application. But these procedures, whenever available, will make treatment more efficient and more certain, and at the same time provide better base line definition. In the new system, all patients, except the elderly and those with congestive heart failure, bradycardia or a history of asthma, are treated first with propranolol alone, a procedure which will diminish or normalize blood pressure in many patients with high and normal renin levels. For nonresponders, diuretic therapy is then superimposed. Subsequently, a propranolol subtraction trial picks out the low-renin patients who will usually respond to a diuretic alone. This program is likely to be fully effective in possibly up to 85 per cent of patients. For the residual smaller fraction, drugs such as hydralazine, methyl DOPA, clonidine, reserpine or guanethidine are then added in traditional trial and error fashion. The proposed system has the theoretic attraction for long-term commitment, implicit in antihypertensive therapy, of achieving blood pressure control in large fractions with one drug instead of two or with two drugs instead of three or more. Moreover, the large groups who respond to therapy with propranolol alone (most high-renin and normal-renin patients) or to diuretics alone (most low-renin patients) gain the advantage of simpler, more specific, long-term (i.e., antirenin or antivolume) therapy. The use of propranolol alone has practical and theoretic advantages over diuretics. Control may be achieved with even fewer side effects and without hypokalemia and chronic dehydration with its possibly adverse consequences (hyperuricemia, azotemia, hyperlipidemia, hyperreninemia, increased blood viscosity). Also, propranolol provides more direct control of the increased peripheral resistance and of neurogenically-induced swings in blood pressure. At the same time, the new system efficiently exploits the long-term use of diuretic therapy alone in low-renin patients in whom volume excess seems a causal factor. And it tends to avoid the use of diuretics in high-renin patients and of beta-blockers in low-renin patients in whom these drug types may be contraindicated.