What Causes Asthma;Can it be Preventive?

Severe asthma attack can be life threatening,right?Asthma is a lung disease that characterized by chronically inflamed and narrow air passages.Asthma attacks manifest as wheezing,chest tightness,shortness of breath and coughing.This is trigger by allergens such as house dust mite,pollen from grass and trees,fur or hair of warm blooded pets like cats,certain foods,cigarette smoke,air pollution,cleaning solutions,paint,chemicals,infections so on.There is no cure for asthma, but asthmatics can live normal.The most common effective measure against asthma is avoidance of triggers but it is difficult to do.So, anti - asthma drugs classified relievers or preventers.Relievers are use during asthmas attacks such as corticosteroids and beta- agonists while preventers are designed to stop occurrence and improve lung function it is usually available in oral or inhalant forms.