Sleep paralysis is a condition in which a person develops a temporary immobility that occurs immediately after falling asleep or waking up. The person remains conscious during a crouching episode, which often involves annoying hallucinations and a choking sensation.
An episode can last from a few seconds to about 20 minutes, and the average duration is between 6 and 7 minutes. About 8 percent of people suffer from sleep paralysis at some point in their lives, but the first symptoms often appear in childhood, starting in the teenage years and frequently in your thirties.