Dehydration and volume depletion: How to handle the misconceptions

Figure 1 Distribution of total body water in various fluid compartments of a 70 kg man (see text for explanation).

Figure 2 Compensatory responses to dehydration and extracellular fluid volume depletion. The kidneys retain what is lost from the body – water conserved in dehydration; salt and water are reabsorbed in extracellular fluid volume depletion. ADH: Antidiuretic hormone; ANP: Atrial natriuretic peptide; ECF: Extracellular fluid; RAS: Renin angiotensin system.