Dehydration occurs when the body does not have as much water and fluids as it should, and can be caused by losing too much fluid, not getting enough fluids, or both. Causes such as vomiting and diarrhea come to mind, but drinking too much caffeine or alcohol are also commons reasons for dehydration.
Symptoms may range from dry mouth and lower urine output to more severe including lethargy and coma. When vomiting and diarrhea are involved dehydration can become severe because fluids cannot be replenished. This will sometimes requires immediate medical attention.
Tests for dehydration include the Comprehensive Metabolic Panel to check electrolytes and blood sugar, as well as a Urinalysis to check the concentration of urine which can indicate the level of dehydration. Additionally, a Complete Blood Count can be used to check for signs of concentrated blood.