$[$ Select $]["$Isotonic$",$ "Hypertonic", "Hypotonic"$]$ dehydration is characterized by elevated serum sodium levels and elevated blood urea nitrogen $($BUN$).$ This is caused by insufficient fluid intake and can occur when equal amounts of water and sodium are lost from the body with diarrhea and vomiting. $[$ Select $]["$Hypotonic$",$ "Hypertonic", "Isotonic"$]$ dehydration takes place when body sodium loss is greater than water, as it occurs with the use of diuretics and excessive sweating. Symptoms of dehydration include: $[$ Select $]["$increased energy and euphoria", "excessive saliva production and increased appetite", "increased pulse, fever, loss of appetite, increased confusion, weight loss, concentrated urine, etc."$].$