How does dehydration change urine composition and urine output?

Dehydration leads to a decrease in urine output as the body conserves water to maintain hydration levels. As a result, urine becomes more concentrated, exhibiting higher levels of solutes such as urea, creatinine, and electrolytes. This change in composition can also cause urine to appear darker in color. Overall, dehydration prompts the kidneys to reabsorb more water, reducing the volume of urine produced.