Cause of asthma

Asthma is a respiratory disease. Worldwide asthma is a major health problem express as mild to severe breathing problem. It is a critical things to understand the cause of asthma. But certain things may trigger to develop asthma. Asthmatic problem become worse with certain factor. These factors are given bellow,  

Dust 

Cold and hot 

Pollen 

Animals dust 

In most case genetics plays a vital role in asthma development. The person having ancestor history of asthma are most vulnerable to asthma development. 

Narrowing of airway passage way is the major cause of asthma development. Allergic reaction narrows the airway. Hence,  allergic reaction causes severe asthma problem.