<prompt> A 57-year-old man is referred for assessment of his low serum sodium of 125 mEqL. On examination, he has pitting edema and elevated neck veins. His urine sodium is 10 mEqL and urine osmolality 350 mOsmkg.For the above patient with hyponatremia, select the most likely diagnosis.congestive heart failure CHFextrarenal sodium and fluid lossesSIADHpolydipsia  <response>: 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. 