What is a common sign of dehydration?

Increased thirst, dry mouth, and decreased urine output are all hallmark signs of dehydration. When the body is low on fluids, it triggers the thirst response to encourage fluid intake, indicating a need for hydration. A dry mouth occurs because there is less saliva produced when the body is dehydrated. Additionally, the kidneys conserve water to sustain the body's fluid balance, which leads to decreased urine output. This response helps to retain as much water as possible when the body is in a state of dehydration. Together, these symptoms provide clear indications that the body is lacking adequate hydration.

The other options do point to various health concerns but do not specifically correlate with dehydration. Increased hunger and fatigue might suggest a different health issue, while excessive sweating and fever could indicate conditions like heat exhaustion or infection, and pale skin with weakness may pertain to anemia or other medical conditions. Therefore, the presence of increased thirst, dry mouth, and decreased urine output specifically signifies dehydration effectively.