For some days presently i own not be breathing resourcefully what may be the create?

I am not ashmatic, so why am i not breathing well it keep me unconfortable,my back feel heavy, pls. support.For some days presently i own not be breathing resourcefully what may be the create?
You are suffering from cold. Go to a doctor for check-up.
It could be bad allergies.
do you own any pets?a bird?or do you smoke?any of these could affect your breathing,doing cardio excercise can help,you own to do it constantly for over 30 mins or something,but then it starts to work your lungs