Mark Klimek Electrolytes and Endocrine Practice Test 2026 - Free Electrolytes and Endocrine Practice Questions and Study Guide

Moon face comes from cortisol excess, as seen in Cushing's syndrome. When cortisol is chronically high, fat is redistributed to the face and trunk and fluid retention adds fullness, producing the round, puffy facial appearance described as moon facies. This pattern helps distinguish it from Addison's disease (weight loss, low blood pressure), hypothyroidism (facial puffiness from myxedema but not the characteristic cortisol-driven rounding), and hyperparathyroidism (bone and metabolic symptoms rather than facial changes).