The more I think about it, knowing that I've been diagnosed with both COPD and then Age-related Asthma Onset, I really wonder if they are the cause of my constant wet coughing? From everything I've been reading, I am not sure my wet cough/Phlegm issue is caused by either of them. Asthma and COPD are typically characterized by cough, shortness of breath and airflow limitations. I do not have shortness of breath or airflow limitations. I wonder if my sinuses could be draining down into my lungs while lying down sleeping at night? Maybe I should be trying over the counter sinus drying products. Your thoughts?