Amnesia

What is amnesia?

Amnesia is when you have serious memory loss. It can be a symptom of other conditions or happen by itself.

Amnesia comes from ancient Greek and means, “forgetfulness.” But it’s more than that. Forgetfulness is misplacing your keys or not remembering to do something while running errands. Amnesia involves being unable to remember significant events or details from your life.

Are there different types of amnesia?

There are two main forms of amnesia. Retrograde amnesia is when you can’t recall memories from your past. Anterograde amnesia is when you can’t form new memories but can still remember things from before you developed this amnesia.

Other forms of amnesia include:

• Post-traumatic amnesia. This is amnesia you develop after an injury. It can involve multiple forms of amnesia.
• Transient global amnesia. This is a short-lived condition that involves both anterograde and retrograde amnesia. It almost always lasts less than 24 hours.
• Infantile amnesia. This is amnesia from when you were a baby. Almost everyone has this. Remembering things from infancy is rare.
• Dissociative amnesia. This is amnesia that happens because of a mental health-related cause. Traumatic events, abuse and other severe sources of psychological distress can cause it. Experts suspect it’s a defense mechanism your brain uses to protect you from what you experience.

How common is amnesia?

Amnesia is uncommon on its own. But it’s a very common symptom of certain conditions. These conditions usually involve brain damage or activity disruptions. An example is Alzheimer’s disease, a major cause of amnesia. About 24 million people worldwide have Alzheimer’s, which accounts for millions of people with amnesia. And there are dozens of other possible causes.

What are the symptoms of amnesia?

Symptoms of amnesia depend on the type you have.

You might experience:

• Changes in your ability to remember events or things that happened to you.
• Difficulty recalling names and faces.
• Not remembering locations and how to get to them.
• Forgetting about upcoming events that you planned to attend.

People with amnesia may also experience something called confabulation. This is when your brain automatically tries to fill in memory details and makes a mistake. An example of confabulation would be misremembering what day an event happened on recently, or the details of an event from your past.

People who have confabulation believe their memory is genuine and accurate. They don’t intend to lie or deceive. It’s just an error that happens without their knowledge. Ordinarily, confabulation is harmless. But it can become a bigger issue and may be something you notice when memory loss is more severe.

What causes amnesia?

Amnesia can happen for many reasons. The causes fall broadly into two main categories: neurological causes and psychological causes.

Neurological causes of amnesia

Neurological causes of amnesia all involve damage to your brain or disruptions in brain activity. The possible causes include (but aren’t limited to) the following:

• Alcohol intoxication (this can temporarily block the formation of new memories, causing a “blackout”).
• Alzheimer’s disease.
• Brain aneurysms.
• Brain tumors (including cancerous and noncancerous growths).
• Cerebral hypoxia (brain damage from lack of oxygen).
• Drugs and medications (especially certain sedatives and anesthesia medications), including nonmedical drug use.
• Epilepsy and seizures (especially temporal lobe epilepsy).
• Frontotemporal dementia.
• Head injuries like concussions or traumatic brain injuries (TBIs).
• Infections (especially ones that cause encephalitis like herpes simplex virus).
• Other degenerative brain diseases, like Parkinson’s disease or multiple sclerosis (MS).
• Stroke.
• Toxins and poisons like carbon monoxide poisoning or heavy metal poisoning.
• Transient global amnesia.
• Wernicke-Korsakoff syndrome (this is a severe vitamin B1 deficiency that happens with long-term alcohol use disorder).

Psychological causes of amnesia

Memory loss can also happen in connection with mental health issues. Examples include dissociative disorders, especially dissociative amnesia, and post-traumatic stress disorder (especially complex PTSD). These cases usually involve a traumatic event, or severe mental or emotional distress. Experts don’t fully understand why it happens, but they suspect it’s your brain’s way of trying to limit or protect you from psychological harm.

How is amnesia diagnosed?

A healthcare provider can usually diagnose amnesia by talking to you and asking questions about yourself, your life, current events and your symptoms. There are also diagnostic tests and imaging scans that can contribute to the diagnosis. The tests that your provider recommends will vary depending on what they suspect is causing your amnesia and if you have other symptoms.

What tests will be done to diagnose amnesia?

Several tests can contribute to diagnosing a condition that causes amnesia or rule out other conditions that might cause it. Imaging scans are among the most common but aren’t the only useful tool.

Possible tests include:

• A physical and neurological exam.
• A neuropsychological assessment.
• Computed tomography (CT) scans.
• Magnetic resonance imaging (MRI) scans.
• Electroencephalogram (EEG) to look for seizure activity in your brain.
• Blood testing (to look for signs of infection, check vitamin and mineral levels, blood sugar levels, etc.).
• Spinal tap (lumbar puncture) to check your cerebrospinal fluid for signs of a possible cause.

How is it treated/is there a cure?

There’s no direct treatment or medication that can cure amnesia. When it happens because of a treatable condition, treating that condition is the best way to reverse it. Because many conditions can cause amnesia, the treatments can vary widely, too. Many times, your brain can recover on its own, and you’ll regain your memory as it does.

People with amnesia may not understand what’s happening to them. They might not be able to make informed choices about their medical care. In those cases, a loved one with the authority to do so may need to make decisions for them.

Cognitive rehabilitation and occupational therapy may also help some with memory loss. These types of therapies can teach you skills and techniques to help you compensate for any loss of memory or related abilities. Rehabilitation and therapy can also help loved ones learn how to support you best.

Can amnesia be prevented, or can I reduce my risk of developing it?

Some causes of amnesia are preventable, but amnesia itself isn’t predictable. People can have a condition that causes it but never develop amnesia as a symptom. Amnesia can also happen for reasons that are completely out of your control.

But you can take some steps to reduce the risk of amnesia happening:

• Wear safety equipment.
• Eat a balanced diet.
• Sleep, rest, relax and manage stress as needed.
• Reach and maintain a healthy weight for you.
• Don’t ignore eye or ear infections, as these could spread to your brain.
• Manage health conditions that could affect your brain.
• Stay mentally active with books, puzzles, etc.
• Maintain social relationships to keep your brain engaged.
• Quit using tobacco products (ask your provider for resources to help with this), or don’t start using them.

What can I expect if I have amnesia?

If you have amnesia, you may not be aware of it immediately. Most people who have it feel disoriented early on. You might also have trouble making sense of the experience because you don’t remember or understand what caused your amnesia. What you can expect may also depend on any other symptoms you have.

In general, your healthcare provider (or your loved one’s provider) is the best person to tell you more about what you can expect. The information they provide will be the most accurate and relevant for your specific case.

How long does amnesia last?

When amnesia affects how you form or store memories (anterograde amnesia), that kind of memory loss is permanent. Amnesia that affects how you retrieve memories (retrograde amnesia) may improve over time, depending on what caused it in the first place.

Memory loss is more likely to be permanent when it happens because of conditions that permanently damage your brain or disrupt how it works (like Alzheimer’s disease). Because this can vary, your healthcare provider (or your loved one’s provider) is the best person to tell you what’s most likely in your situation.

How do I take care of myself?

People with amnesia can often compensate for their memory loss in multiple ways. Some use lists and notes to compensate or use smartphone apps or other forms of technology. Family, friends and loved ones may also help by supporting your efforts to regain your memories (if and when it’s possible) and recover from whatever caused your amnesia.

People with amnesia from degenerative brain diseases or who have anterograde amnesia (and can’t form or store new memories) usually need support or medical care 24/7 (like with family members or in a skilled nursing facility).

When should I see my healthcare provider/When should I seek care?

If you have memory loss that begins and develops slowly, you might not be able to recognize it in yourself. It’s more likely that a loved one will notice it first. If you notice it in yourself, asking for help is a good idea. Everyone needs support at some point, and there’s no shame in admitting that you need it.

Often, a loved one will be the first to notice signs of memory loss. If you notice it in someone you care about, they may not want to admit that something’s wrong or might not feel like that’s the case. If that happens, it’s best to do and keep the following in mind:

• Listen and ask how you can help.
• Encourage them to see a healthcare provider.
• Reassure and offer empathy and compassion.
• Stay calm, don’t argue and don’t take resistance personally.
• Don’t be afraid to ask for help or resources yourself.

If a loved one needs more care and support than you can offer, don’t be afraid to look for alternatives or ask for help. Seeking long-term care options for a loved one might be the best way to keep them safe and maintain their quality of life.

When should I go to the hospital or emergency room?

Sudden memory loss in yourself or someone you’re with is always a sign to get medical attention. That’s the best, safest course of action regardless of whether there’s an obvious cause.

If you have any kind of memory loss after a head injury or an impact that might cause whiplash, you need medical attention immediately. Even if you don’t pass out, not remembering an injury right after it happens could be a sign of a concussion or traumatic brain injury.

What questions should I ask my provider?

If you notice possible signs of memory loss, you may want to ask your provider the following:

• What’s causing my memory loss?
• Is memory loss normal in my circumstances?
• Are there any medications that can help with the disorder causing my amnesia?
• Will my memory get better or worse over time?
• What can I do to help myself and preserve my memory and brain function?
• How can my family and friends help me?
• What resources or services are available that might help me?
• Would I benefit from therapy or cognitive rehabilitation options?
• Can you recommend mental health resources like a psychiatrist and therapist (if needed)?

Can amnesia affect motor skills and make me forget how to do common activities or tasks?

Amnesia rarely affects motor skills. When you learn how to do something, like swim or ride a bike, your brain stores memories of how to do it in a different part of your brain. That’s why amnesia doesn’t typically affect motor abilities or learned skills.

Can amnesia change your personality or erase a person’s identity?

No, your memory lives in a different part of your brain than the areas that hold personality and behavior. While you can have damage to both, having damage to one area doesn’t automatically damage the other.

Is mild cognitive impairment (MCI) the same as amnesia?

No, amnesia and mild cognitive impairment are separate. You can have both at the same time (like with degenerative brain diseases or head injuries), but they aren’t the same.

Is amnesia common when you drink alcohol?

Alcohol can disrupt the formation of new memories, but you usually have to be significantly intoxicated for that to happen (the common term for this is a “blackout”). Binge drinking may increase the chances of this happening. The definition of binge drinking is a single session where you have five or more drinks (if you’re assigned male at birth or AMAB), or four or more drinks (if you’re assigned female at birth or AFAB).

How does memory work?

Your memory is like your brain’s recording of important events or details about your life. Think about it like a library of what happened in your life. Creating that library involves the following steps:

• Encoding: This is when your brain creates the memory. It’s like your brain typing and publishing a memory in book form.
• Storage: This is how your brain stores the memory. It’s like your brain filing the book away in your library. Your brain also tags the memory so you can return and find it, if necessary.
• Retrieval: This is when you go back into your library, open the book and review what was in it.

Memory formats

Your brain has different memory formats depending on how long you need to store a memory. Those formats are:

• Working memory (immediate recall). This is how you remember the topic of a conversation you’re part of, a phone number you’re writing down, etc. It’s like your brain’s version of scratch paper and stores information for no more than 10 minutes or so.
• Short-term memory. These are memories that you store for slightly longer than working memory. Your brain converts working memories to short-term memories when you need to hold onto information for longer. Short-term memory stores information for about an hour.
• Long-term memory. This is when your brain converts short-term memories for permanent storage. In theory, your brain can store long-term memories for the rest of your life (but retrieval may not always work correctly, which is why long-term memory loss can happen).

Types of memory

You have different forms of memory, explicit (declarative) and implicit (nondeclarative). Amnesia only affects explicit memory.

• Explicit (declarative) memory. These are memories you can access when you want to recall something. Explicit memory includes semantic memory (like facts or basic descriptions of events) and episodic memory, which is when you recall the details and nuances of the memory.
• Implicit (nondeclarative) memory. These are things you know even without remembering how you learned them. An example of this would be knowing how to tie your shoes or brew coffee or tea.

A note from Cleveland Clinic

Your memory is a key part of who you are, so not being able to remember something can be a scary experience. If you’re experiencing memory loss or have a loved one showing signs of it, you should talk to a healthcare provider. Despite how it looks on TV or in movies, sudden memory loss isn’t common. And many of the conditions that cause memory loss are treatable. Your healthcare provider can help you better understand what could be causing memory loss, what you can do about it and how you can reduce its impact.