You’re reviewing labs and see a sodium level of 122 mmol/L—cue exam alert! Hyponatremia, or low serum sodium, is a deceptively simple yet highly testable condition on both Step 1 and Step 2 CK.

In this blog, we’ll walk through the mechanisms, major causes, and classic clinical presentations of hyponatremia—and show you how to dominate questions with a King of the Curve visual aid.