Different types of hallucinations you experience during sleep paralysis

Well, when you are in REM you breathing patterns are shallow and your airways are constricted making it hard to breathe anyway. The symptom involves the threat-activated systems in the amygdala making the sufferer feel like someone is strangling or suffocating them.

A choking feeling because of shallow breathing during sleep paralysis (Wikimedia Commons)

2. Intruder Hallucinations

People experiencing the intruder hallucinations experience the feeling of a presence of an intruder, fear, visual and auditory hallucinations. In addition to incubus, the sufferer's mind develops a vision to solve a sort of paradox that occurs during sleep paralysis.

Hallucinate about someone intruding your sleep (Wikipedia)

This leads the body into a state called “hyper-vigilant state of mind,” making people aware of the slightest stimuli and only seem to recognize the cues towards threats and danger. Even a small sound can seem terrifying during sleep paralysis and evidently, the incubus and intruder hallucinations go hand in hand.

3. Unusual Bodily Experiences

This type of sleep paralysis hallucination is uncommon, in which people have an out of body experience. These experiences are the ones when you feel like you are flying around the room or feel like you have had an unusual encounter, which is least likely to be probable. This is different from the others, since different parts of the brain are active, which is similar to the condition when the person awoke.