The Laragh Method is based on the concept that normal blood pressure is maintained by the amount of salt in the body (arterial volume, V in the diagram), and plasma renin activity (PRA) (R in the diagram) working together. Normally when body salt is high PRA becomes low, and when body salt is low PRA becomes high. These reactive changes in PRA stabilize BP(1).
Hypertensive patients are not all alike. They may be hypertensive because they have too much body salt, or a PRA level that is too high, or both. This means that they also differ in their BP response to drugs that either salt deplete or block the renin-angiotensin system.
The Laragh Method uses the clinical PRA test to guide antihypertensive treatment. It is useful for unsuccessfully treated patients. The PRA HTN App guides this process step by step.