One of the reasons I was motivated to quit smoking was that my mouth, nose and eyes were always really painfully dry. I have a condition due to rheumatoid arthritis that causes my membranes to be dryer than they should be anyway, and smoking was making it worse. vaping can be dehydrating though as we all know…so I've found that I still have to use saline spray and often an ointment called Rhinaris (I can get it OTC at the drugstore here in the US) at night before I go to sleep. Overall, it is still much better than it was when smoking. BUT, even with years of dryness, I'd never had a nosebleed (barring being bonked in the nose). Then, about a month after starting vaping, me and the hubby traveled from North Carolina (where we live is essentially a humid swamp) to Vegas (dry desert) and two days after we landed I was minding my own business and BOOM…it was like a fountain. It was terrifying…but just because the dry air was exaggerating my already sort of dry nose. I'm guessing replacing my usual excessive water intake with free bloody marys from the hospitality bar wasn't helping matters either. 
TL;DR unless it starts happening all day every day, your nose is probably just dry and irritated. Try a water-based ointment and nasal saline spray. (Don't stick a petroleum-based ointment up your nose. It can be dangerous.)
TL;DR unless it starts happening all day every day, your nose is probably just dry and irritated. Try a water-based ointment and nasal saline spray. (Don't stick a petroleum-based ointment up your nose. It can be dangerous.)
Do you mean in the general sense - like breathing, or only when vaping? 
