Dehydration occurs when you use or lose more fluid than you take in, and your body doesn't have enough water and other fluids to carry out its normal functions. If you don't replace lost fluids, you will get dehydrated.Anyone may become dehydrated, but the condition is especially dangerous for young children and older adultsThe most common cause of dehydration in young children is severe diarrhea and vomiting. Older adults naturally have a lower volume...