what is the reason for my baby having heavy cough especially at night time during sleep for about 15 days continuously and she cough so difficulty daily at night her sleep gets diturbed..and also at the day time she doesn't cough much but she has continues running nose.. and this running nose is continuously happening from 1and1/2months and it never gets stops for any medicine or it doesn't gets stop even for a day..may I know the reason and treatment please..