Prescribing Safety Assessment (PSA) Practice Exam 2025 - Free Prescribing Safety Practice Questions and Study Guide

Euvolemic hyponatremia is a condition characterized by a low sodium level in the blood while maintaining a normal fluid volume. The condition is often caused by various physiological mechanisms, with the most notable being the inappropriate secretion of antidiuretic hormone (ADH), which is seen in the syndrome of inappropriate secretion of antidiuretic hormone (SIADH).

In SIADH, excess ADH leads to water retention, dilution of serum sodium, and consequently euvolemic hyponatremia. This reflects an actual impairment in the body’s ability to regulate fluid balance, rather than a true depletion of body sodium or fluid volume.

In contrast, diarrhea typically causes loss of both water and sodium, which usually results in hypovolemic hyponatremia. Renal artery stenosis leads to impaired blood flow to the kidneys, often resulting in fluid retention and elevated blood pressure, but this does not directly lead to euvolemic hyponatremia.

Thus, the specific pathophysiological mechanism observed in SIADH directly corresponds to the state of euvolemic hyponatremia, whereas the other options relate to scenarios that would typically lead to different types of hyponat