- The type of dehydration characterized by a greater loss of water compared to electrolytes is known as hypertonic dehydration.

- In hypertonic dehydration, the loss of water exceeds the loss of sodium and other electrolytes, leading to an increased concentration of electrolytes in the extracellular fluid.
- This results in the extracellular fluid becoming more concentrated (hypertonic) relative to the intracellular fluid, causing water to move out of cells to balance the osmotic gradient.

This contrasts with:
- Hypotonic dehydration, where there is a greater loss of electrolytes than water, leading to diluted extracellular fluid.
- Isotonic dehydration, where water and electrolytes are lost in approximately equal amounts, maintaining normal osmolality.
- Osmotic dehydration is not a commonly classified type of clinical dehydration.

Thus, the hallmark of hypertonic dehydration is the disproportionate loss of water relative to electrolytes, which increases serum sodium levels and causes cellular dehydration. Recognizing the type of dehydration is crucial for appropriate fluid management.

Reference: Harrison’s Principles of Internal Medicine, 20th Edition, Volume 1, Chapter 40 – Fluid and Electrolyte Disorders