A nightmare is an unpleasant dream. Nightmares cause strong unpleasant emotional responses from the sleeper, typically fear or horror. The dream may contain situation(s) of danger, discomfort, psychological or physical distress. Such dreams can be related to physical causes such as a high fever; in an uncomfortable or awkward position; stress or post traumatic experiences. Sometimes there may not readily be an explanation. If a person has experienced a psychological trauma, the said experience… (More on Nightmare)