What is the primary function of aldosterone?

Aldosterone is a steroid hormone primarily produced by the adrenal glands, and its main role is to regulate salt and water balance in the body. It achieves this by promoting the reabsorption of sodium in the kidneys. When sodium is reabsorbed, water follows passively, which helps to maintain fluid balance and blood volume. This process is crucial for overall homeostasis, as it directly influences blood pressure and the body's hydration status.

While it's true that aldosterone indirectly impacts blood pressure through its effect on blood volume, the primary function centers on the regulation of salt (sodium) and water balance. This hormonal regulation is vital in managing conditions like hypernatremia and hyponatremia, as well as overall electrolyte levels. Other options such as regulating glucose levels or stimulating red blood cell production do not pertain to aldosterone's functions, as those are managed by different hormones and physiological processes.