Asthma is a term used to describe a range of different diseases, but we can try to make it simple by talking about two main types: allergic and non-allergic asthma.
is caused by allergies. Most people with this kind of asthma also have other types of allergic conditions like eczema and hay fever. They react to common substances like house dust, mite and pollen called allergens.
Allergens tend not to cause any reaction in the majority of people. But in those who are allergic, their immune system overreacts and starts fighting the perceived threat. Since there is nothing to attack, the damage gets inflicted on the cells of the body.
is caused by other factors like work-related exposure to chemicals.