Hello
Your room mate is a nurse , so I will try to explain , why she is having
cough .
1 Bornchitis or chronic
bronchitis :cough for most of the time at least for three consecutive months for at least 3-4 consecutive years .
Cough may be associated with sputum production or without sputum.
Patients have
wheezing ,
sore throat , cough and symptoms of
common cold .
This is usually due to acute exacerbation of chronic bronchitis .
2 Asthmatic allergic bronchitis , as this may be the next cause of such symptoms . Usually dust , mite , pests , pollen , molds fine dusting powder are the triggering factors responsible for such cough .
3 Bronchiectais as this is also a common cause of such cough but int his there is large amount of expectoration or phlegm present .
In my opinion your room mate may have asthmatic ( asthma ) or allergic bronchitis as both these two disease are not contagious , so need not to worry.
Hope this information will be helpful for you.