This document provides an overview of hypertension, its mechanisms, classifications, and treatments, specifically focusing on various antihypertensive drugs such as ACE inhibitors, angiotensin receptor blockers, and diuretics. It explains the actions of these medications on the renin-angiotensin system and outlines therapeutic uses, contraindications, and side effects associated with key drugs like captopril, enalapril, and ramipril. Additionally, it discusses the relationship of hormones like aldosterone and bradykinin in regulating blood pressure and electrolyte balance.