Question: why hyponatremia in myxedema coma?
Answer: The hyponatremia seen in myxedema coma is a result of decreased free water clearance. Elevated levels of antidiuretic hormone and/or diminished blood flow to the kidneys are believed to be responsible for the inability to excrete free water. 19,20 Hyponatremia is classically associated with a low serum osmolality.