Amnesia is what doctors call a loss or disturbance of memory. It is a loss of memory, that is to say, a person cannot remember certain things. Amnesia can be caused when someone has brain damage, a disease or when something really stressful happens.

There are two "main types":

• Anterograde amnesia: Short term memory is not transferred to long-term memory any more. People with this type of amnesia cannot remember things for long periods of time.
• Retrograde amnesia: The person can no longer recall information that happened before a certain date. The date is usually the date of an accident or an operation.