We all have fear from time to time. Paranoia is beyond that — way beyond. People who are paranoid see enemies around every corner and under every rock — everyone is an enemy, and sometimes they distrust even their friends.
Paranoid people sometimes go to great lengths to relieve the tension of their constant fear, engaging in overly cautious or, paradoxically, overly reckless behavior. At the extreme, they invent narratives that don’t exist and aren’t happening in the real world, and begin behaving as though they are real.
It starts to get pathological when the fearful imaginings dominate the consciousness of the person. If this person has power over others, then those people may be brought into the invented world of the paranoid individual.
Paranoia is thought to contribute to or be an aspect of paranoid personality disorder, malignant narcissism, drug abuse, and schizophrenia. It factors in to a number of sociological phenomenon including conspiracy theories, aggression, antisocial behavior, conflict in general, and more.