If there are two words Dr. James Findling, an endocrinologist at the Medical College of Wisconsin, dreads hearing, they’re probably “adrenal fatigue.” Some of his patients recite claims they’ve read on social media: that adrenal fatigue happens when the adrenal glands, which produce the stress hormone cortisol, can’t keep up with the amount of stress they’re facing and underperform, leading to a long list of symptoms.