What is amnesia?

Amnesia is a partial or total loss of memory. It can affect a person's ability to remember information that was learned before or after a specific point in time. Amnesia can be caused by physical trauma, such as a blow to the head, or by psychological trauma, such as abuse or neglect. Certain medications, surgeries, and neurological conditions can also cause amnesia.

Amnesia is classified into several types, including:

Anterograde amnesia - occurs after the onset of brain injury or disease. In this type of amnesia, new memories cannot be formed, but previously learned memories remain intact.

Retrograde amnesia - occurs before the onset of brain injury or disease. In this type of amnesia, previously learned memories are lost, while memories formed after the injury or illness remain intact.

Transient global amnesia - a rare neurological condition characterized by sudden, temporary memory loss that typically lasts for several hours. The specific cause of transient global amnesia is unknown, but it is thought to be related to a brief interruption of blood flow to the brain.

Childhood amnesia - the inability to recall memories from early childhood (before the age of three or four). This type of amnesia is considered normal and is thought to be related to the development of the brain.

Psychogenic amnesia - also known as dissociative amnesia, is a psychological condition in which memory loss is caused by psychological trauma. This type of amnesia can be temporary or long-lasting.