It’s normal to forget a word, misplace your keys, or have trouble remembering directions once in a while. These kinds of memory slips become more common as you get older. But sudden memory loss — such as suddenly forgetting your children’s names or not knowing where you are — can signal a more serious problem.
Sudden or acute memory loss is usually due to a disease, condition, or event (like surgery) disrupting the way parts of your brain works. This differs from progressive memory loss, in which your memory gets worse over time as some of your brain cells deteriorate. This happens with Alzheimer’s disease and other types of dementia.
The good news is sudden memory loss is usually treatable. Here are some things that can lead to it — and what you can do about them.
Many prescription drugs can affect your memory. Often, this is because they block the effect of a brain chemical called acetylcholine. Acetylcholine plays a role in memory, learning, and paying attention. People with Alzheimer’s often have low levels of acetylcholine. Some of the most common drugs that may cause memory loss are:
Anxiety drugs. Alprazolam (Xanax), chlordiazepoxide (Librium), clonazepam (Klonopin), diazepam (Valium), flurazepam (Dalmane), and lorazepam (Ativan)
Drugs to treat depression. Amitriptyline (Elavil), clomipramine (Anafranil), desipramine (Norpramin), doxepin (Sinequan), imipramine (Tofranil), and nortriptyline (Aventyl, Pamelor)
High blood pressure medications. Atenolol (Tenormin), captopril (Capoten), metoprolol (Lopressor, Toprol), propranolol (Inderal), and sotalol (Betapace)
Cholesterol-lowering drugs. Atorvastatin (Lipitor), fluvastatin (Lescol), lovastatin (Mevacor), pravastatin (Pravachol), rosuvastatin (Crestor), and simvastatin (Zocor)
Pain medications. Fentanyl (Duragesic), hydrocodone (Norco, Vicodin), hydromorphone (Dilaudid, Exalgo), morphine (Astramorph, Avinza), and oxycodone (OxyContin, Percocet)
Antiseizure drugs. Acetazolamide (Diamox), carbamazepine (Tegretol), gabapentin (Neurontin), lamotrigine (Lamictal), pregabalin (Lyrica), and valproic acid (Depakote)
Medicines for sleep disorders. Eszopiclone (Lunesta), zaleplon (Sonata), and zolpidem (Ambien)
If you take one of these drugs — or even something not on this list — and are worried about your memory, ask your doctor if you can switch to something else.
A 2018 review of earlier studies found that people having depression had a reduced ability to recall memories. One possible explanation is that when you’re depressed or stressed, levels of the hormone corticosteroid rise in your body — and they stay high if you’re in a state of stress or depression for a long time. High levels of corticosteroid can damage memory signals in the brain.
Some types of antidepressant drugs may also increase the risk of memory loss, studies show. If you’re on antidepressants and have memory loss, talk to your doctor about changing your medicine.
Too little vitamin B12 in your diet can also affect your memory. This nutrient helps your body use energy from food, and it protects nerve cells so you can think clearly.
Your body doesn’t make vitamin B12. You get it from animal products such as meat, fish, milk, cheese, and eggs. Some vegans might not get enough vitamin B12 from diet alone. If you’re low in this vitamin, ask your doctor about taking a supplement.
The thyroid gland in your neck produces hormones that control how quickly your body burns food for energy. When your thyroid makes too little of its hormones — called hypothyroidism – your whole body slows down. You can feel tired, depressed, and forgetful.
Your doctor will do a blood test to check your thyroid hormone levels. If they’re low, you’ll get thyroid hormone pills.
If you binge drink — have many drinks in a short time — you may sometimes “black out.” This means you have no or only partial memory of what happened while you were binge drinking. You might not remember holding certain conversations or having sex, for instance.
Alcohol stops your brain from forming new long-term memories. This problem increases with the amount of liquor your drink. Binge drinking and doing drugs together can increase the chance of a blackout. If you keep drinking too much, memory loss can become permanent.
A fall, car accident, or other hard knock to the head can leave you unable to remember people or events. Even if the injury doesn’t knock you unconscious, it can lead to sudden memory loss.
Depending on how severe the hit to your head was, the memory issues might go away within 24 hours or be permanent.
A stroke happens when a blockage or weak area in a blood vessel cuts off blood flow to part of your brain. Without oxygen-rich blood, brain cells start to die. A stroke can cause short-term or long-term memory loss. You might start forgetting things you’ve learned or get easily confused.
To protect your blood vessels and prevent more strokes:
Damage to the brain from a tumor or its treatments can affect memory. Chemotherapy, surgery, and radiation can affect your ability to think clearly or remember. It’s sometimes known as “chemo brain” or “chemo fog.” Cancer can also make you so tired that you can’t think straight.
Take care of yourself while you’re being treated for cancer. Eat well and get plenty of rest to save energy and keep your memory.
A brain aneurysm means there’s a bulge in a weakened blood vessel. It usually doesn’t cause problems unless it ruptures. But a doctor will need to monitor it to prevent it from rupturing. Problems with short-term memory can be a sign that you have an unruptured brain aneurysm.
Another source of sudden memory loss is TGA. With this condition, you don’t remember recent events, like where you currently are, and you may ask the same questions over and over. But you’ll know your name and the names of loved ones. Your symptoms of confusion and memory loss are usually gone in less than 24 hours.
The cause of TGA is not clear. You usually don’t have a head injury or a seizure beforehand. Many doctors think it may be related to migraine because as many as 30% of people with TGA have had migraine attacks. Others believe it might be due to a problem with blood flow in your body, where your veins might have too much blood due to a blockage (vascular congestion). One big risk factor for TGA is age. It mostly affects people over 50.
This type of amnesia is usually spontaneous and can happen after:
- Sudden immersion in cold or hot water
- Emotional upset
- Intense exercise
- Some scope procedures used to diagnose disease
- Sex
TGA is rare and doesn’t need to be treated. It should get better on its own.
Everyone forgets things once in a while, no matter their age. But you may want to talk to a doctor if the following things are happening to you:
- Asking the same questions over and over
- Getting lost in places you know very well
- Having trouble following directions or recipes
- Becoming confused about people, places, or dates
- Not taking care of yourself — not bathing, dressing, or eating
If you’re noticing some of these signs, see your doctor. They will ask questions about your symptoms and do tests to find out what’s behind the problem. Many causes of sudden memory loss can be treated.
Sudden memory loss can be caused by things as varied as alcohol-related blackouts, cancer treatments, strokes, and taking different medications. Treatment depends on the cause of memory loss, but in most cases, the problem will go away after you find out the reason for it.
How do you fix short-term memory loss?
It may depend on the reason for the memory loss. For instance, if it’s due to taking a certain medication, then stopping it should make the memory loss disappear. General tips for improving memory include staying physically and mentally active by exercising and playing word games or reading, spending time with others to lessen depression and stress, getting enough sleep, and eating a healthy diet.
What do you do if someone is losing their memory?
If you think your loved one is losing their memory, have them checked out by a doctor. The doctor will do a physical exam and ask about their diet, medications, and health history, as well as possibly do a brain scan. If it’s a sudden memory loss, it should eventually get better. In the meantime, be patient with your loved one. It’s distressing for them to not remember things. Try to give verbal cues. So rather than saying “Lisa is on the phone. Remember her?” say, “Lisa, your cousin, is on the phone.” Write down anything important your loved one needs to remember.
Is sudden memory loss an emergency?
Yes, it is. If a loved one has sudden memory loss, call 911 or go with them to the hospital. Because they’ll be unlikely to remember recent events, you’ll have to tell the doctors what was happening just before your loved one lost their memory.
