Which type of dehydration is defined by a decreased blood sodium concentration?

Hypotonic dehydration occurs when there is a loss of more sodium than water in the body, leading to a decreased blood sodium concentration, which is also known as hyponatremia. This typically results from conditions such as excessive fluid intake or fluid loss from sources like diarrhea or sweating that is not replaced with adequate sodium.

In hypotonic dehydration, the osmotic balance between the intracellular and extracellular fluids is disrupted, causing water to move into the cells, potentially resulting in cellular swelling. This situation is often characterized by low serum osmolality, and symptoms can include nausea, headache, lethargy, and confusion.

Understanding this type of dehydration is crucial in pediatrics, as children are especially vulnerable to electrolyte imbalances and fluid shifts that can lead to serious complications if not promptly recognized and addressed.