Detailed Instructions: Given a scientific passage and an answer, generate a question for the given answer.
Q: Passage: Asthma is a disease in which bronchioles in the lungs periodically swell and fill with mucus. Symptoms of asthma may include difficulty breathing, wheezing, coughing, and chest tightness. An asthma attack may be triggered by allergies, strenuous exercise, stress, or another respiratory illness such as a cold. Answer: asthma
A:
What is the disease in which bronchioles in the lungs periodically swell and fill with mucus?