Answer:
Asthma occurs often because of certain "triggers". Each person's triggers differ but can include just about anything, such as dust, smells, fumes, good-smelling aromas like cooking smells or perfumes, etc. Asthma occurs because of inflammation and irritation in the lungs, thus causing less lung expansion and impaired oxygen-carbon dioxide exchange. Asthma can also cause reduced respiratory effort-- the muscular part of breathing-- so that breathing is more shallow. Since alcohol acts as a respiratory depressant in the way it acts on the brain, just like prescription or street drugs can cause, ingestion of alcohol can trigger an asthma attack due to reducing the respiratory effort and depressing the brain's respiratory center.