“…No gross and specific physical signs betray water retention-pitting oedema is absent, although, while water retention was present in this case, we convinced ourselves that the face appeared, and felt, more tense and " full " than before or afterwards. Evidence suggests that the symptoms are essentially due to hypotonicity of extracellular ,C~/'V,/Np'~.. fluid (Wynn and Garrod, 1955). These authors recommend that water-diuresis tests should be avoided unless the serum sodium is above 130 mEq/l.…”