Aldosterone acts mainly on the kidneys, specifically on the distal tubules and collecting ducts. It promotes the reabsorption of sodium (Na+) and the excretion of potassium (K+). By increasing sodium reabsorption, aldosterone also promotes water retention, which helps to increase blood volume and, consequently, blood pressure. This process is part of the larger renin-angiotensin-aldosterone system (RAAS), which is critical in regulating cardiovascular function.
