Memory loss is a blanket term which is used to describe a wide range of medical conditions, primarily including amnesia and dementia. Amnesia is the temporary or permanent loss of memory; this memory loss can cover part of all of the patient’s life, or be limited to a relatively short period of time or a single event. Causes of amnesia include trauma resulting from a blow to the head, or exposure to a very psychologically stressful event. Dementia is a form of memory loss associated with aging, in which the patient gradually loses more and more cognitive ability. It is an important early indicator of Alzheimer’s disease.