This book provides a detailed review of the biological importance of the renin-angiotensin-aldosterone (RAAS) axis in the maintenance of human physiological functions and blood pressure homeostasis, and its regulation and manipulation via currently available pharmacological methods. In addition, this book review targets both the beneficial and detrimental effects of the RAAS axis in the context of cardiovascular and renal pathology, collectively termed the cardio-renal metabolic syndrome. Signaling pathways and direct interactions leading to crosstalk between RAAS and other growth and metabolic pathways are explored. Pharmacological means targeting the various components of the RAAS, including angiotensin receptor blockers, ACE inhibitors, aldosterone receptor antagonists and others are discussed.