8 causes of short-term memory loss and how to combat it

• Short-term memory loss is common and can be something as simple as misplacing your car keys.
• Usually, short-term memory loss is temporary and not a concern.

Short-term memory loss is common and strikes often. Examples include meeting someone and immediately forgetting their name, misplacing your car keys, or walking into a room and forgetting why you're there.

"It's a universal experience," says Samantha Holden, MD, neurologist and clinical director of outpatient neurology at UCHealth.

Note: Officially, short-term memory refers to things that have happened within the last 30 seconds. However, the term is often used interchangeably with "working memory," which refers to the way that our brains process, store, and recall information. This is the definition that this article will use.

Short-term memory loss is a normal part of aging, but can also be brought about by medical conditions like depression or a brain injury, says Sanam Hafeez, PsyD, psychologist and founder of Comprehensive Consultation Psychology Services.

Continue reading to learn about what can cause short-term memory, what's normal, and when you may need to see a doctor.

1. Head injury

Memory loss, both short- and long-term, is a common symptom of a concussion, even if you don't black out, says Holden.

Concussions are a type of traumatic brain injury and can occur as the result of any strong or immediate impact to the head like from a car accident, sports injury, or fall.

What do do about it: Short-term memory loss from a head injury generally goes away within a few months and there's really no way to speed up that process. However, if you experience warning signs like persistent memory loss, loss of consciousness, confusion, trouble walking, or unusual eye movement, then you should seek medical attention.

As you slowly regain your short term memory, you can help your brain out with tactics like writing things down or always putting items in the same place.

"The brain loves structure and routine, so putting as much structure and consistency as you can into your day will help the brain remember better," Holden says.

Now, a single head injury probably won't impair your memory long-term, but many head injuries can. For example, a small 2018 study of college athletes with concussions found that 21% experienced a long-term impact on their working memory.

And over time, these repeated injuries can increase the risk of dementia. Therefore, it's important to prevent head injuries by always wearing a helmet and seatbelt and avoiding unnecessary risks, Holden says.

2. Aging

Aging is the most common cause of short-term memory loss. About 11% of adults over the age of 45 report subjective cognitive decline, which includes memory loss, says Hafeez. By age 60, 40% of people experience some memory loss.

As people age, certain areas of the brain shrink, communication between regions of the brain becomes less effective, and blood flow to the brain can slow.

That leads to normal age-related memory impairment, where people may have more trouble multitasking or become more forgetful, but their day-to-day ability to live independently is not impacted.

What to do about it: "Typically, short-term memory loss is not anything to be concerned about," Hafeez says.

Make sure to stay mentally active by engaging in activities like reading, writing, or other hobbies. You can also use lists and routines to help you remember things you find yourself easily forgetting.

It's also important to get enough exercise, sleep, and nutrients as these are all very important for healthy brain function including memory.

However, if you find yourself forgetting whether you ate or took medication, speak with a doctor.

Important: Normal age-related memory impairment is not a sign of dementia. Dementia is chronic memory-related cognitive decline, which affects about 7% of adults over their lifetime.

3. Drinking too much

Blackouts occur when drinking too much alcohol disrupts the brain's ability to transfer memories from short to long-term. When that happens, you typically wake up not remembering what happened while you were drinking.

Blackouts are most common when a person has a blood-alcohol content of 0.16 or higher. However, you don't have to be blackout drunk in order for alcohol to impact your memory, says Holden.

A large 2021 brain imaging study found that any alcohol can reduce gray matter, which is associated with more significant memory loss.

"Any intake no matter the amount on a regular basis, has negative effects on our brain function," Holden says.

What to do about it: Evaluate whether you are drinking too much, and make a plan to cut back.

"You don't have to be a teetotaler, but be aware that any amount of regular intake is going to have negative effects," Holden says.

4. Lack of sleep

Memories are stored in the brain during non-rapid eye movement sleep. So, in order to have a healthy functioning memory, you need to get into those deep stages of sleep, which typically occur within the first hour after falling and staying asleep and within cycles throughout the night, says Holden.

During sleep, your brain also activates the glymphatic system, which clears waste from the brain to keep the central nervous system operating at its best when you're awake. If the glymphatic system isn't able to do its job, your brain will be less effective at remembering things the next day.

A poor night's sleep leaves you "running on not only an empty gas tank the next day, but also as if you haven't had your oil changed," Holden says.

What to do about it: Get the recommended 7-9 hours of sleep each night. Implement a sleep hygiene routine to help yourself fall asleep faster and stay asleep. Finally, address any underlying conditions like depression, insomnia, or sleep apnea that might be causing you to lose sleep.

"Sleep apnea is an extremely common cause of memory trouble," says Holden. "And once you treat the apnea the memory goes back to normal."

5. Depression

One of the most common causes of short-term memory loss in people younger than 50 is mood disorders, including depression, says Holden.

People with depression are more likely than their peers to report memory problems, and depression has been linked to trouble recalling information and remembering. Doctors are still working to understand why, but it's not surprising to Holden that depression affects memory.

"It changes our brain chemistry and electrical signaling in our brain," she says.

What to do about it: Talk to your doctor about your depression symptoms and get treatment. That might include talk-therapy and medications like SSRIs.

Some people have memory improvements after treating depression, while others experience permanent impairments. Even if you're not able to alleviate depression, cognitive rehabilitation — therapy to improve brain function after an injury — may improve memory, according to a small 2015 study.

6. PTSD

Post-traumatic stress disorder, or PTSD, is a mental health disorder that includes having anxiety or flashbacks after experiencing trauma. People with PTSD often have intense, even invasive memories of the traumatic event. Yet, PTSD is associated with reduced cognitive function and trouble with short-term memory.

"In addition to the too much memory of the bad stuff, there's also some downplaying of other memories because so much of that energy is being put towards the traumatic event," says Holden.

What to do about it: Treatment for PTSD can include talk therapy, exposure therapy, or EMDR. Research is ongoing about whether treating PTSD will restore memory function, but it can improve overall quality of life.

7. Malnutrition

What you eat — or don't eat — can impact your brain health and memory function.

Most of the research about malnutrition and memory loss has focused on people with dementia, but the research indicates that being malnourished can increase the risk for memory loss as well as make pre-existing memory loss worse.

When patients present with short-term memory loss, Holden makes sure they're getting enough of two key nutrients: vitamin B1 (thiamine) and vitamin B12 (folate). Being deficient in either is associated with memory problems.

Other symptoms of B12 deficiency include, anemia, unexplained weight loss, tiredness or weakness. A B1 deficiency can cause loss of appetite and weight loss, nerve problems including tingling, blurred vision, and nausea.

Note: People who drink too much or have undergone weight loss surgery are at increased risk for both these deficiencies, says Holden.

What to do about it: Eat a healthy, macronutrient-rich diet like the Mediterranean diet, which includes a lot of seafood, lean meat, and plant based whole foods like nuts that are rich sources of B vitamins.

"Anything that's good for our bodies is good for our brain, so we always recommend that people get as many colors and fresh items in their diet as possible," Holden says.

Talk to your doctor about taking a multivitamin or supplement containing B1 or B12.

8. Dementia and neurological disease

Short-term memory loss is normal and common. For most people, it will not lead to dementia or severe memory loss. However, in rare cases short-term memory loss can be an early sign of dementia, which includes conditions like Alzheimer's.

Short-term memory loss becomes cause for concern when it leads to mild cognitive impairment, or MCI, which can precede more serious memory decline. People with MCI have memory issues that are significant enough that they and their loved ones notice. But, they're still able to function day to day.

"When we do thinking and memory testing we see objective impairments on their tests, but they are still fully functionally independent: paying their bills, managing their medications, driving, shopping," Holden says.

However, about 10% to 15% of people with MCI will go on to develop dementia.

What to do about it: People with MCI should see their doctor for testing and monitoring. Early diagnosis is important for treatment, which can delay the onset of dementia and can help prevent or delay more severe symptoms.

How to prevent short-term memory loss

Living a healthy lifestyle may keep your brain healthy and help you remember things, says Hafeez.

"Simple things like eating right, sleeping well, and staying socially active will help counter the issue of memory loss," she says.

Moreover, engaging your brain can help keep you sharp. You don't have to do crossword puzzles, but challenge your cognition by learning new skills like games, crafts, hobbies, or languages, says Holden.

Note: There are currently no brain training exercises that have been clinically proven to reduce the risk of dementia or boost memory.

Insider's takeaway

Everyone experiences short-term memory loss occasionally. Aging, illness, and injury can all make short-term memory worse, so reach out to your doctor if you are concerned about your forgetfulness, says Holden.

Otherwise, use routines, lists, and structure to help yourself remember what you need to do, and rest assured that short-term memory loss usually isn't a cause for concern.

"Those little lapses here and there are completely normal and actually a healthy part of our brain function and memory," Holden says.