The Role of Renin-Angiotensin System in Fluid Balance

When your body is depleted of fluids, it activates the renin-angiotensin system, causing you to retain sodium. Only when there is a significant volume loss does it trigger the release of ADH and water retention. A graph in the show notes illustrates that around 10-15% volume loss is needed for this response. Many patients who are volume depleted, such as those with UTIs, may not develop hyponatremia because the volume loss is not enough to stimulate ADH release.