A 57-year-old man is referred for assessment of his low serum sodium of 125 mEq/L. On examination, he has pitting edema and elevated neck veins. His urine sodium is 10 mEq/L and urine osmolality 350 mOsm/kg.For the above patient with hyponatremia, select the most likely diagnosis.
Hyponatremia associated with nephrotic syndrome, cirrhosis, or CHF is characterized by edema. It is believed that the hyponatremia is caused by a decrease in "effective" circulating volume secondary to decreased cardiac output or sequestration of fluid.
congestive heart failure (CHF)
extrarenal sodium and fluid losses
SIADH
polydipsia
Oncology