I have sleep apnea and I have been using a cpap machine for about 5 years now. I have not been back to do another sleep study because of no insurance. I had pneumonia 3 weeks ago and ever since then in the morning after I use my cpap, I wake up with a cough . I start coughing in the middle of the night but it is not productive. I had a chest xray done a couple days ago and normal results. I clean my humidifier tank every so often do I need to clean the inside of the cpap or have it sent away to be cleaned? Any ideas would be greatly appreciated.