How can I tell if I'm dehydrated?

Studies show approximately 75% of Americans regularly experience mild to moderate dehydration. Some signs to look out for include dizziness, headaches, muscle cramps, fatigue, aches & pains, dry skin, brain fog, extreme thirst, dry mouth and decreased urine output. In children, you might notice sunken eyes. And in infants, look for a sunken fontanel (the soft spot on the top of a baby's head) and an absence of tears.