What effect does dehydration have on kidney function?

Dehydration significantly impacts kidney function, primarily by decreasing urine output. When the body is dehydrated, it triggers various physiological responses aimed at conserving fluids. The kidneys play a crucial role in this process. They respond to low fluid levels by concentrating urine to retain as much water as possible, leading to a decrease in the volume of urine produced.

The hormone aldosterone, which promotes sodium retention, and antidiuretic hormone (ADH), which increases water reabsorption in the kidneys, are both elevated during dehydration. These hormones signal the kidneys to absorb more water back into the bloodstream, thus reducing the amount of urine excreted. Consequently, the kidneys work to conserve water to maintain blood volume and pressure, which is critical for overall body function.

This understanding underscores the importance of hydration for maintaining optimal kidney health and function, as dehydration can lead to various complications, including acute kidney injury if sustained over time.