Sleep-related hallucinations are a type of parasomnia, a sleep disorder characterised by undesired events occurring during slumber.
Sleep hallucinations are imagined happenings that seem incredibly real. Most of the time they are visual, but the other senses such as sound, touch, smell and taste may be affected as well, even a feeling of movement.
It can be difficult to distinguish between a state of dreaming and reality. You may not be certain if you are conscious or unconscious; these situations may seem like a bad dream, but when you awaken from it, you understand that it happened during sleep. Nightmares are distinguished as false and not considered genuine.
You may experience complex visual hallucinations in the form of stationary images of people or animals, which typically occur when you are abruptly awoken. Unlike other dreams, you don't remember being in the middle of one when you wake up and realise that you are indeed awake. In such a case, it is not uncommon to feel afraid and think that these images are real, often resulting in a sudden outburst and potential injuries.
These visuals can present in the form of a distorted shape or size, staying for several minutes before disappearing after turning on a light. Although uncommon, these episodes can be linked to migraine-induced head pain, soon following the visual images.