Dr. Moritz raises an important issue. We reported an overall hospital mortality rate of 41% in 103 patients who were admitted with hypernatremia or developed the condition during hospitalization. Hypernatremia was judged to be a significant comorbid factor in the deaths of 16% of the patients on the basis of the severity of underlying diagnoses and comorbid conditions and of the temporal relation between hypernatremia and death, even though no deaths were directly attributable to hypernatremia (for example, intracranial bleeding caused by cerebral dehydration). Although delayed or inadequate treatment of hypernatremia was not associated with a statistically significant increase in overall mortality (inadequate treatment, 49%; appropriate treatment, 32%; P = 0.12), deaths in which hypernatremia was a contributing comorbid factor were significantly more frequent when treatment was delayed or inappropriate (inadequate treatment, 25%; appropriate treatment, 8%; P = 0.046). Similarly, in the subgroup of patients with hospital-acquired hypernatremia, the condition was a significant comorbid factor in the deaths of 24% of patients who had inadequate treatment and in the deaths of only 5% of patients treated appropriately (P = 0.029). No differences were seen in the subgroup of patients who had hypernatremia on admission, but this may have been a result of the small sample size. Thus, although inappropriate treatment of hypernatremia was not associated with a significant increase in overall mortality, it was associated with a significant increase in the rate of deaths in which hypernatremia was a contributing comorbid condition.