Why do I have cold symptoms all the time. I have a bad cough and am coughing up green mucus. I'll go for maybe 3 or4 maybe 5 days without coughing then it starts up again. This has been going on for months. I have been on antibiotics 3 times. I also have asthma but it's completely under control with Dulera My doctor or maybe I should say my nurse practitioner is diagnosing it as allergies.