Table 2.

Conditions associated with high water intake: Those in which high water intake is indicated or not indicateda

Conditions for which high fluid intake is indicated to prevent disease
    urolithiasisGenerally, fluid intake should achieve a urine volume of 2.0 to 3.0 L/d
Conditions for which high fluid intake is recommended because of underlying disease
    salt-wasting nephropathy (medullary cystic disease, other causes of chronic interstitial kidney disease)Very rare disease; high salt intake (e.g., >400 mM/d NaCl) may be required to avoid hypotension; because these patients cannot appropriately concentrate the urine, high fluid intake (e.g., >4 L/d) may be needed
    central and nephrogenic diabetes insipidus (genetic or acquired, e.g., lithium nephrotoxicity)These patients often cannot raise urine to levels isosmotic with plasma; often large water intakes (e.g., >5 L/d) are needed to maintain water balance and a normal plasma osmolality
Conditions for which high fluid intake is not recommended
    inappropriately high NaCl intake (′salt gluttony′) in the patient with CKDThe high NaCl intake “drives” the fluid intake; 24-h urine collection for creatinine (to assess completeness of the collection) and NaCl (to assess NaCl intake) will detect this condition; the appropriate management is to decrease salt intake
    primary polydipsia because of the mistaken belief that high fluid intake is good for the kidneyThis practice should be discouraged
  • a CKD, chronic kidney disease.