MEASUREMENT OF BODY WATER

Abstract

A satisfactory method for the measurement of total body water in the living subject has long been sought. This is not surprising when one pauses to consider the overwhelming importance of water in the body economy. Water furnishes the preponderant single molecular element in the fabrication of tissue. Its presence is essential to the great mass of chemical reactions on which life depends. It furnishes the means of transport of virtually all enzymes, substrates, metabolites, gases, electrolytes, antibodies, and other substances that must be moved to and from the cell. Cellular function itself is affected by abnormal fluctuations in water content. The methods that have been employed for the measurement of total body water may be considered under three general headings: desiccation procedures, body specific gravity measurements, and dilution techniques. DESICCATION The first estimates of body water content were accomplished with desiccation procedures. One of the early studies in man