... nephrogenic) Chapter 046. Sodium and Water (Part 3) Hypovolemia Etiology True volume depletion, or hypovolemia, generally refers to a state of combined salt and water loss exceeding intake, ... Na+ and water loss 1. Diuretics 2. Osmotic diuresis 3. Hypoaldosteronism 4. Salt-wasting nephropathies C. Renal water loss 1. Diabetes insipidus (central or nephrogenic) Chapter 046. ... disorders are due to impaired secretion of and renal unresponsiveness to AVP, respectively, and are discussed below. II. ECF volume normal or expanded A. Decreased cardiac output 1. Myocardial,...