How do I know which one? My 5 month old dd has had a runny nose(clear) for a few days an has had a cough...she normally sleeps through the night but the last few nights she's been coughing and waking herself up...i feel so bad for her..,I've even giving her Tylenol at night and using a vaporizer but if its teething is this gonna last awhile? I miss my sleep...lol