What effect does aldosterone have on blood pressure?

Aldosterone primarily affects blood pressure by promoting sodium retention in the kidneys. This retention leads to an increase in blood volume, since sodium causes water to be reabsorbed in conjunction with it. When more water is retained, the overall blood volume rises, which can lead to an increase in blood pressure. This mechanism is crucial in the body’s regulation of blood pressure, especially in response to situations where there is low blood volume or low blood pressure.

Sodium retention, along with the associated water retention, results in greater venous return to the heart, which increases cardiac output and contributes to higher arterial pressure. Thus, aldosterone plays a significant role in the complex renin-angiotensin-aldosterone system (RAAS) that works to maintain blood pressure within a normal range, particularly during states of hypovolemia or hypotension.