If you or someone you know has passed out and dismissed it as nothing more than dehydration, it’s time to think twice. Here’s why fainting deserves a deeper look: 1. Not all fainting is “just fainting.” Cardiac syncope can be life-threatening. Think arrhythmias, obstructive lesions, or severe structural heart disease. It’s not always benign. 2. The most dangerous cause of syncope is often invisible on physical exam. Conditions like ventricular tachycardia or heart block may not show up during a