Dehydration caused by diarrhea remains a major source of morbidity and mortality worldwide. Dehydration is a common clinical presentation seen by most physicians. Clinical diagnosis depends on the recognition of signs and symptoms as well as change in weight. Laboratory studies are helpful in categorizing the dehydration as isotonic, hyponatremic, or hypernatremic, which is necessary to plan appropriate therapy. In many situations, oral rehydration therapy is possible and desirable. Intravenous rehydration remains the standard of care for children with severe dehydration and shock. PMID: 2070768 [PubMed – indexed for MEDLINE]