Does having asthma affect being an air hostess?

How severe: Most people's asthma can be controlled with medications , allergen avoidance, +/- allergy shots. Although an air hostess is more exposed to allergens and scents carried on the passengers' clothing , viral infection, and lower oxygen level in the cabin, he/she should be able to do the job if the asthma is under good control. The story would be different if he/she suffers from frequent attacks.

Possible: It depends on what your triggers are, but yes it is possible

Probably not : A good unless Asthma is mild and we'll controlled. Air pressure and exposure to a whole spectrum of allergens and difficulty with getting adequate help or treatment if severe exacerbation occurs. This my personal professional opinion