Your post is very vague. Too cryptic to decipher and be able to effectively help you. In the absence of more information right now, I agree with the others that this sounds like a mental health issue that requires medical attention. She's in trouble and needs medical intervention.
I agree 100% w/ both Nighthawk61 and specialmom; your girlfriend needs to seek medical attention for this.
Aside from mental health issues, do you know if she is taking any medications or abusing any drugs, or has had any head injuries? If you are able to, you should consider speaking w/ her family out of concern for her.
Hi. I agree. This sounds psychological in nature and something it would be wise for your girlfriend to get some help for. It's hard to understand exactly what is going on from your description but know that you can not 'save' anyone--- they have to save themselves and she sounds like she does need some medical help for some mental health issues. No shame in that, many people do. good luck
Are you saying that when she creates these imaginary friends, she get's nosebleeds etc to the point of collapsing? I think that's what you mean but i see a period in between freely and when, so it's not clear to me.
I think that your girlfriend needs to see a Physician and have them refer her to a Psychiatrist. If the creation of these imaginary friends manifest's itself into harmful behavior or physical harm, they need to go away.
Also, how old is your girlfriend? Can you tell us more about the imaginary friends? do they have names ? you say she can feel them? like touching her arm? have they harmed her, or been sexual with her? Do the same friends come back time and time again? Has she been diagnosed with Schitzophrenia or does it run in her family? .