Amnesia is when an individual loses all or some of their memory.
It can be caused by a blow to the head, brain illnesses, or an extreme emotional experience.
Anterograde amnesia - when the individual struggles to remember regular or day to day events and activities after a physical injury or accident.
Retrograde amnesia - when the individual struggles to remember events or activities that happened before their injury.
Transient global amnesia - disruption to the memory that lasts for around 4-12 hours normally following trauma.
Fugue amnesia - when the individual cannot remember who they are and struggles with identity.
More top news
A dry day across the region with bright or sunny spells after a frosty start. However, cloud will tend to increase from the west by evening.
After a cold, bright and frosty start, skies will gradually turn cloudier through the afternoon. However, it will stay dry with light winds.
An engineer has been confirmed dead in the crash in Wales. The RAF say the pilot survived and is receiving treatment.