- Allergens such as dust, dust mites, animal fur, pollen - chemical irritants such as cigarette smoke, air pollution, odor - Climate change - a viral infection of the respiratory tract - medicine, for example. aspirin- Foods such as seafood
- allergens such as dust, what dust, animal dander, pollen - Passenger irritation such as cigarette smoke, air pollution, smell - changes of the air - the infected of respiratory system - medicine such as an aspirin - food, such as sea food