Water: mechanism of oral rehydration, water deficiency = deficiency in salt.

UNICEF, the United Nations International Children Emergency Funds, has staged an enormous program to improve children's health conditions in the developing countries. One extremely fruitful field of engagement was, and still is, the treatment of dehydration. Oral rehydration therapy (ORT) has reluctantly been accepted in the industrialized countries. From clinical observations, we have gained a new understanding of known pathophysiological principles. Dehydration most often is a result of diarrhea, and therefore oral rehydration therapy is mostly referred to in the context of infections of the digestive system. We discuss additional causes of dehydration and its immediate and secondary consequences. We demonstrate not only that, but why and how, a very simple, inexpensive regimen is beneficial and effective in the treatment of dehydration. Without consideration of sodium deficit, understanding will fail, and treatment will remain ineffective.