"Popcorn lung" is a nickname for bronchiolitis obliterans, a condition that damages the smallest airways in the lungs and makes you cough and feel short of breath. It was first identified in workers in a microwave popcorn factory who breathed in diacetyl, a buttery-flavored chemical used in popcorn, caramel, and dairy products. When inhaled, diacetyl causes bronchiolitis obliterans, which is why it is commonly referred to as "popcorn lung". However, other chemicals or lung illnesses can also cause popcorn lung.

E-cigarettes have also been linked to popcorn lung because some e-cigarette companies add diacetyl to their "e-juice" liquid to complement flavorings such as vanilla, maple, and coconut. However, e-cigarettes do not cause popcorn lung. There have been no confirmed cases of popcorn lung reported in people who use e-cigarettes.

The symptoms of popcorn lung include coughing, wheezing, and shortness of breath, similar to the symptoms of chronic obstructive pulmonary disease (COPD). Popcorn lung is a rare disorder, but it can happen to anyone since it can result from an infection or exposure to certain substances.

To prevent popcorn lung, it is important to avoid exposure to the chemicals that cause it. If you work in a job that exposes you to these chemicals, you should use the recommended protective equipment. If you smoke or vape, you should quit. Treatments for popcorn lung may include medications, oxygen therapy, and pulmonary rehabilitation.

In summary, popcorn lung is a serious lung disease that damages the smallest airways in the lungs and makes it harder for you to breathe. It can be caused by breathing in chemicals such as diacetyl, which is commonly found in popcorn flavorings and some e-cigarettes. To prevent popcorn lung, it is important to avoid exposure to the chemicals that cause it and to quit smoking or vaping.