Dehydration

Definition:

The lack of adequate body fluids for the body to carry on normal functions at an optimal level (by loss, inadequate intake, or a combination of both). Losses of only a few percent in an adult and up to 5% in infants are considered mild dehydration.

Causes, incidence, and risk factors:

Dehydration can be caused by excessive loss of water from the body as in:

• vomiting
• diarrhea (especially well recognized in cholera)
• excessive urine output (polyuria)
• sweating, excessive

Dehydration can also occur from inadequate intake as in:

• nausea
• stomatitis or pharyngitis
• acute illness with loss of appetite

Dehydration in children is most often a combination of both as in:

• stomach flu with vomiting and diarrhea
• acute illness where the child refuses fluids and loses excessive fluid through sweating with fever

Fluid losses up to 5% are considered mild; up to 10% are considered moderate; and up to 15% are considered severe. Severe dehydration can result in cardiovascular collapse and death if not treated quickly.