It is unknown where in the brain dreams originate, if there is a single origin for dreams or if multiple portions of the brain are involved, or what the purpose of dreaming is for the body or mind.
While many theories have been proposed, no single consensus has emerged as to why we dream. Some researchers suggest that dreams serve no real purpose, while others believe that dreaming is essential to mental, emotional and physical well-being.
Dreams mainly occur in the rapid-eye movement (REM) stage of sleepwhen brain activity is high and resembles that of being awake. Dreams can last for a few seconds, or as long as twenty minutes. People are more likely to remember the dream if they are awakened during the REM phase. The average person has about 3 to 5 dreams per night, but some may have up to 7 dreams in one night. Dreams have been seen as a connection to the unconscious. They range from normal and ordinary to overly surreal and bizarre.