In SIADH, which electrolyte abnormality is most characteristic?

Unlock all questions

This demo includes only 20 questions. Upgrade to access hundreds of questions, flashcards, exam simulations, and disable ads.

Full question bankExam simulationsFlashcards
From $25.99Unlock all

Study for the NBME Form 13 Test with our comprehensive quiz collection, featuring flashcards and multiple-choice questions to ensure your readiness. Enhance your knowledge with detailed explanations for each question.

Multiple Choice

In SIADH, which electrolyte abnormality is most characteristic?

Explanation:
SIADH causes the kidneys to hang onto too much water because ADH is secreted inappropriately. This dilutes the serum sodium, so the hallmark is hyponatremia with a low plasma osmolality. Even though sodium is low, the body remains euvolemic (often with concentrated urine), and the urine is inappropriately rich in sodium and osmolality. So the characteristic electrolyte abnormality is hyponatremia. Hypernatremia would suggest a water deficit or lack of ADH, not this syndrome, and potassium or calcium abnormalities aren’t defining features here.

SIADH causes the kidneys to hang onto too much water because ADH is secreted inappropriately. This dilutes the serum sodium, so the hallmark is hyponatremia with a low plasma osmolality. Even though sodium is low, the body remains euvolemic (often with concentrated urine), and the urine is inappropriately rich in sodium and osmolality. So the characteristic electrolyte abnormality is hyponatremia. Hypernatremia would suggest a water deficit or lack of ADH, not this syndrome, and potassium or calcium abnormalities aren’t defining features here.

More Multiple Choice Questions
Subscribe

Get the latest from Passetra

You can unsubscribe at any time. Read our privacy policy