Thanks for your question on Healthcare Magic.
I can understand your concern.
Yes, you should definitely change your CPAP machine tubings once in every 3-4 months.
You should definitely also clean your tubings every 15-20 days with warm water.
This is standard practice for tubings and their cleanliness.
If you are not having following this practice then you may get
lung infection acquired from tubings.
So to rule out lung infection, you should
consult pulmonologist and get done clinical examination of respiratory system and chest
x ray.
Chest x ray is must for the lung infection.
Don't worry, you will be alright.
Follow standard practice for tubings and their cleanliness.
Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks.