Which hormone helps maintain blood pressure during dehydration?

Aldosterone plays a crucial role in maintaining blood pressure, particularly during states of dehydration. This hormone, produced by the adrenal cortex, regulates sodium and potassium levels in the body. When dehydration occurs, the body’s fluid volume decreases, which can lead to a drop in blood pressure.

In response to low blood volume and pressure, the kidneys release renin, which activates the renin-angiotensin-aldosterone system (RAAS). Aldosterone promotes the reabsorption of sodium in the renal tubules. As sodium is reabsorbed, water follows by osmosis, leading to an increase in blood volume and, consequently, blood pressure. This process is essential for conserving water and maintaining cardiovascular stability during periods of dehydration, ensuring that vital organs remain adequately perfused.

Other hormones mentioned, such as insulin, thyroxine, and cortisol, do not have a direct role in regulating blood pressure in response to dehydration. Insulin primarily regulates glucose metabolism, thyroxine influences metabolic rate and growth, and cortisol, while it can impact blood pressure through fluid retention and vascular responsiveness, does not have the same direct and critical role as aldosterone specifically during dehydration.