<s>[INST] I have been using my CPAP for 1.5 years for sleep apnea without any problems. Two months ago I was away for 3+ weeks (family emergency) without my CPAP. I arrived home very tired and without thinking to wash out my CPAP, I just filled the container and went to bed. Shortly after, I developed a severe cough and then developed a severe breathing problem. Short of breath just getting dressed, or doing any menial chore. I have had two different diagnosis - pneumonia then asthma. After two months I am getting worse rather than better. Question: Any possibility the non use of CPAP could have caused a lung fungus? [/INST] Yes there is a high chance that as the CPAP was not used for the 3 weeks you were away, it built up fungus in the mask due to the humidity.And as you must have used it later without washing it properly, it can lead to the fungal infection.However not necessary that it is a fungal infection, it can be a bacterial infection also. Get a CT chest done and see a chest physician with the reports </s>