She thought vaping was harmless — a sweet escape flavored with fruit and calm. Then her lungs began to burn.

Doctors call it “popcorn lung.” Once rare, it’s now appearing in younger adults who believed vaping was safe. The condition scars the smallest airways of the lungs, making every breath a battle. Its name comes from factory workers in the early 2000s who inhaled a buttery flavoring chemical while packaging microwave popcorn — and never recovered.

That same chemical, diacetyl, hides inside many flavored vapes. “It causes inflammation and scarring in the bronchioles,” experts warn. “There’s no cure — only symptom control.” In severe cases, patients may even need a lung transplant. The scariest part? Many illegal or unregulated vape brands still contain it, especially outside the EU.

Across the U.S., more young people are turning to vaping every year, unaware of the long-term price. A soft cough, a wheeze, or shortness of breath — often dismissed — can be the first whisper of irreversible damage.

Breathing is something most of us take for granted — until it’s gone. “Prevention, not treatment,” one doctor said quietly. “That’s the only real cure.”