Asthma is a physical disorder brought on by a number of inciting events. Not everyone with asthma responds to all of these inciting events. The most frequent triggers for an asthma attack include a viral illness, exercise, exposure to cold air, and exposure to specific plants and animals or chemicals that you are sensitive to. House dust contains several elements that can trigger an asthma attack. This is something to consider when attacks come year-round.
Emotional stress can also trigger asthma.
Environmental contamination, such as we have in winter with increased chemical and particulate matter held in the air during an inversion, can also trigger asthma or make it worse. Asthmatics are characterized by having airways that are overly responsive to these triggers. When a specific exposure triggers an asthmatic attack, the body responds by constriction of the small airways in the lungs. This is accompanied by increased mucous production. The lungs also develop an inflammatory response that complicates this disease.