What are common signs of dehydration in adults?

Common signs of dehydration in adults include dark yellow or amber-colored urine, decreased urination frequency, and feeling thirsty. Physical symptoms include dry mouth, dry skin, fatigue, dizziness, and headaches. More moderate to severe dehydration can cause rapid heartbeat, rapid breathing, sunken eyes, confusion, and fainting. A simple way to monitor hydration is to check urine color, which should be pale yellow when properly hydrated. Mild dehydration can often be resolved by drinking water or electrolyte-containing beverages, but severe symptoms like confusion or fainting require immediate medical attention.