Nightmares are dreams with vivid content that occur during REM sleep. They usually involve immediate awakening and good recall of the dream.
Night or Sleep Terrors are often described as extreme nightmares that take place during non-REM sleep. They usually include agitation, large pupils, sweating, increase in blood pressure, screaming and appearance of being terrified. Parents are awakened but the child does not usually wake up and does not remember in the morning. They are distressing for the person who has them and for their family.
A typical cause of Night Terrors is Sleep-Related Breathing Disorder. When a child’s brain is not receiving proper oxygen at night while they are asleep, Night Terrors is just one of the many symptoms.