The two main features of amnesia are:
- Impaired ability to learn new information following the onset of amnesia (anterograde amnesia)
- Impaired ability to recall past events and previously familiar information (retrograde amnesia)
Most people with amnesia have problems with short-term memory — they can't retain new information. Recent memories are most likely to be lost, while more remote or deeply ingrained memories may be spared. Someone may recall experiences from childhood or know the names of past presidents, but not be able to name the current president or remember what month it is or what was for breakfast.
Isolated memory loss doesn't affect a person's intelligence, general knowledge, awareness, attention span, judgment, personality or identity. People with amnesia usually can understand written and spoken words and can learn skills such as bike riding or piano playing. They may understand they have a memory disorder.
Amnesia isn't the same as dementia. Dementia often includes memory loss, but it also involves other significant cognitive problems that lead to a decline in the ability to carry out daily activities.
A pattern of forgetfulness is also a common symptom of mild cognitive impairment (MCI), but the memory and other cognitive problems in MCI aren't as severe as those experienced in dementia.
Additional signs and symptoms
Depending on the cause of the amnesia, other signs and symptoms may include:
- False recollections (confabulation), either completely invented or made up of genuine memories misplaced in time
- Confusion or disorientation
When to see a doctor
Anyone who experiences unexplained memory loss, head injury, confusion or disorientation requires immediate medical attention.
A person with amnesia may not be able to identify his or her location or have the presence of mind to seek medical care. If someone you know has symptoms of amnesia, help the person get medical attention.