People who drink too much coffee are in danger of having illusions and seeing ghosts during the day according to a new research. Our body releases a hormone called cortisol whose production is triggered by caffeine. This hormone actually leads to illusions and hallucinations. This research is directly linked to the intake of caffeine which is major content of coffeine. However, caffeine is also present in tea and chocolate. So research has also linked caffeine to miscarriages of birth problems about women.