Thanks for your question on Healthcare Magic.
I can understand your concern.
Yes, constant
post nasal drip can cause irritation and inflammation of the airways (bronchitis) and this bronchitis can cause constant phlegm and breathing difficulty.
So better to
consult pulmonologist and get done
1. Clinical examination of respiratory system
2. Examination of nose and pharynx
3. PFT (pulmonary function test).
You will need antihistamine and anti allergic drugs for post nasal drip.
On the basis of severity on PFT, you may need long acting inhaled
bronchodilator (formoterol or salmeterol) and inhaled
corticosteroids (budesonide or
fluticasone).
Don't worry , you will be alright with all these.
First diagnose yourself and then start appropriate treatment.
Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks.