What is a common sign of dehydration?

Dark yellow urine is a common sign of dehydration because urine concentration increases as the body loses fluids. When the body is adequately hydrated, urine tends to be light yellow or clear, indicating efficient kidney function and adequate fluid intake. Conversely, a darker color in urine typically signifies that waste products are more concentrated due to insufficient water, prompting a change in color.

While dry skin and fatigue can also be symptoms of dehydration, they are not as direct indicators as urine color, making dark yellow urine a more specific sign. Clear urine reflects proper hydration, while fatigue can stem from various factors, making it a less reliable marker for dehydration specifically.