Astma in toddlers

My two year old son has asthma and has had four episodes of pneumonia actually right now he has it again for the fourth time and also has the flu. Is it normal for a child to have so many episodes of this. He goes to a pediatric pulmonologist and has a sweat test and a swallow test done they were both negative. What could be the reason for this it is always in his left lung Please help!!!!!!!!!!!!  

[Victoireh]

Welcome to the asthma community!

It sounds like he may have bronchiectasis. It's when there is damage in the airways due to infection. The damaged airway is wider and can has pockets where the mucous can accumulate, thus setting up the right environment for bacteria to grow. But I'm not a doctor, so your pulmonary specialist would be better able to diagnose his condition. I would certainly persist on getting a proper diagnosis, so that he can receive the best possible treatment.