Transient global amnesia is a sudden, temporary episode of memory loss that can't be attributed to a more common neurological condition, such as epilepsy, transient ischemic attack, stroke or head injury. During an episode of transient global amnesia, your recall of recent events simply vanishes, so you can't remember where you are or how you got there. You may also draw a blank when asked to remember things that happened a day, a month or even a year ago. You do remember who you are, and you recognize family members and others you have known for a long time, but that knowledge doesn't make your memory loss any less disturbing.

Transient global amnesia would be even more distressing if it recurred more often or lasted longer than it does. The condition is rare to start with, and among the few who do have one episode, a second episode is uncommon. Also, episodes of transient global amnesia last only six hours, on average — although an episode of any length is frightening to witness or experience.

When an episode of transient global amnesia is over, you remember nothing that happened while your memory was impaired, and you might not recall the hours beforehand. Otherwise, though, your memory is fine. 

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