Pathophysiology of Hypertension

Role of the Renin-Angiotensin-Aldosterone System (RAAS)

Hypertension, commonly known as high blood pressure, is a complex condition that involves various physiological mechanisms. One of the key regulatory systems implicated in hypertension is the Renin-Angiotensin-Aldosterone System (RAAS).

Understanding RAAS

The RAAS plays a crucial role in maintaining blood pressure and fluid balance. It is activated in response to decreased renal perfusion, leading to a cascade of hormonal interactions:

• Renin release: The kidneys release renin when there is reduced blood flow or sodium levels.
• Angiotensinogen conversion: Renin catalyzes the conversion of angiotensinogen to angiotensin I.
• Angiotensin II formation: Angiotensin I is converted to angiotensin II via angiotensin-converting enzyme (ACE).
• Aldosterone secretion: Angiotensin II stimulates aldosterone release from the adrenal glands, promoting sodium and water retention.

Impact of RAAS on Hypertension

Chronic activation of RAAS leads to sustained vasoconstriction and sodium retention, increasing blood volume and systemic vascular resistance. This contributes to persistent hypertension and end-organ damage.

Clinical Implications

Targeting RAAS with pharmacological agents such as ACE inhibitors, angiotensin receptor blockers (ARBs), and aldosterone antagonists is a key strategy in managing hypertension.

Conclusion

RAAS is a vital system in the regulation of blood pressure. However, its dysregulation contributes significantly to hypertension, necessitating targeted therapeutic approaches.