What is a common symptom of dehydration?

Dark urine is a commonly recognized symptom of dehydration because it is a direct indicator of the body's hydration status. When the body is well-hydrated, urine typically appears light yellow or clear due to high fluid intake, which dilutes the concentration of waste products. However, as dehydration occurs, the kidneys conserve water, leading to more concentrated urine that takes on a darker color. This change acts as a signal to individuals that they may need to increase their fluid intake to restore proper hydration levels.

In contrast, increased appetite does not correlate with dehydration; in fact, it may sometimes decrease. Excessive sweating can occur during physical activity or in hot conditions but is not a direct symptom for assessing dehydration on its own; it might indicate the body is losing fluids but does not confirm lower hydration levels unlike dark urine. Heightened alertness also does not typically relate to dehydration, as dehydration often leads to fatigue and reduced cognitive function.