A sudden loss of memory is one symptom of an amnesia disorder. Amnesia refers to a partial or complete loss of memory that can be temporary or permanent. It can affect a person's ability to recall past events, retain new information, or both. There are different types of amnesia, including retrograde amnesia (loss of memory for events that occurred before the onset of amnesia) and anterograde amnesia (inability to form new memories after the onset of amnesia). Amnesia can be caused by various factors such as brain injury, stroke, certain medical conditions, psychological trauma, or substance abuse. Treatment and management of amnesia depend on the underlying cause and may involve therapy, medication, and addressing any contributing factors.