On the inappropriate in hypertension research.

The concept of the "inappropriate" has a well-defined and easily comprehended meaning when applied to tumour secretion of antidiuretic hormone (A.D.H., vasopressin). When applied to high A.D.H. in other situations such as nephrotic syndrome, congestive cardiac failure, or cirrhosis, the use of the term "inappropriate secretion" simply reflects the fact that an easily measured controlling factor (plasma tonicity) is being overridden by a less easily measured one (effective extracellular volume). Similarly, sodium excretion in hypertension is said to be inappropriately low for the raised renal perfusion pressure: in this case inappropriateness results from the antinatriuretic effect of a minor degree of sodium depletion produced by pressure natriuresis. A similar objection can be made to the application of the term to the relations between renin or angiotensin-II concentrations and blood-pressure in some forms of hypertension. Since inappropriateness merely reflects the position and predilections of the observer, the widespread use of the term should be abandoned.