Patients struggling with hard-to-detect conditions, such as long COVID; or with symptoms whose causes modern medical testing has trouble pinning down, such as irritable bowel syndrome, can feel dismissed when a doctor says they can’t find a cause for the ailment, or—worse—when they suggest that the condition may be all in the patient’s head. This is commonly known as “medical gaslighting,” a problem that is hardly new but one that social media has amplified in recent years.