A chronic inflammation in the bronchial tubes (airways) causing swelling and narrowing (constriction) of the airways is known as Asthma, it is also known as Reactive Airway Disease.
Due to this a person has difficulty to respire. With treatments the bronchial narrowing is reversible may be totally or at least partially. Chronically inflamed Bronchial tubes might become very sensitive to irritants (non specific triggers) or allergens (specific triggers).
A situation might arise where airways can become “twitchy” due to which they would remain in a state of increased sensitivity which is called “bronchial hyper reactivity” (BHR). In case of the sensitive individuals it is more likely that the bronchial tubes would swell and further constrict being exposed to triggers like allergens, exercise or tobacco smoke.
For such individuals dust is the main asthma trigger. It may be advised that such person wears respirators in order to prevent the dust from entering their system and cause diseases like asthma.