most helpful answer thanks for giving such great detail in your post. it's very helpful. of course i can't diagnose you by internet (i can't diagnose you at all legally) but here's my take on the situation: although your cpap is humidified the bright red blood you're seeing probably is in fact due to your airway becoming dehydrated from the air flow during sleep. generally speaking bright red blood "in" a body substance (mucus stool) isn't really "in" the substance -- it's "on" it. and when blood is "on" another body fluid it means it originated elsewhere such as from torn tissue. i wish i could offer you some advice about how to resolve the situation. you might try lubricating your nasal passages with a small amount of water-based lubricant (like k-y jelly; not petroleum jelly or lotion or anything like that) to see if it helps. a small amount of k-y jelly rubbed just inside the nostrils before bed often solves issues like minor nosebleeds and even tissue dehydration from a cpap. i know you said you're a mouth-breather but you still might give it a whirl. if the situation doesn't clear up within a couple of weeks definitely check with your healthcare provider about it. many people discontinue the use of cpap machines for reasons such as the one you're describing and that's not good. if you have sleep apnea you definitely need to continue using your cpap. while it may be unrealistic to aim for complete comfort with zero side effects from using the cpap your provider may be able to help you find a way to be comfortable while using this life-saving device. wishing you well!
can a cpap machine cause blood in the sputum? . i started using a machine a week ago. first with pillows which did not work because of my sinuses and now with a full mask. it has humidity in it. i am 57 yrs. old. i have never had blood before when i cough up what drained down during the night. i am coughing very little. the blood is bright red. i am a mouth breather because my sinuses are always clogged up. is that small amount of blood anything to be concerned about? '