Understanding the Renin-Angiotensin-Aldosterone System (RAAS) and Hypertension

The Renin-Angiotensin-Aldosterone System, often called RAAS, is important for understanding high blood pressure, known as hypertension.

Here’s a simple break down of how it works:

1. Renin Release:

   • When your blood pressure gets low, your kidneys release a substance called renin.
   • This renin helps change a protein made in the liver called angiotensinogen into another substance called angiotensin I.

2. Angiotensin Converting Enzyme (ACE):

   • In your lungs, angiotensin I is changed into angiotensin II by an enzyme known as ACE.
   • Angiotensin II is very important because it helps raise blood pressure.

3. What Angiotensin II Does:

   • Narrowing Blood Vessels: It makes blood vessels tighten, which increases the resistance against blood flow and raises blood pressure.
   • Releasing Aldosterone: It tells the adrenal glands to release a hormone called aldosterone. This helps the kidneys hold onto more sodium and water.
   • More fluid in your body means higher blood pressure.

4. Feedback Loop:

   • If RAAS keeps working too much, it can lead to long-term high blood pressure.
   • This can put extra stress on the heart and might lead to problems like heart failure or hardening of the arteries.

In short, RAAS plays a big role in causing high blood pressure by increasing both resistance in blood vessels and the amount of fluid in your body. This can lead to serious heart and health issues over time.