What Is Brain Fog? Symptoms, Causes, and Treatment

Do you ever notice that your ability to think feels sluggish or fuzzy? You might be experiencing what’s commonly known as “brain fog.” While not technically a medical or scientific term, it describes a temporary sensation of reduced mental acuity.

The emergence of hustle culture, which created legions of overworked achievers, brought awareness to the cognitive challenges that go with it. Lingering brain fog has also been a common side effect during recovery from the COVID-19 viral illness. Brain fog related to menopause can lead to trouble with concentration and difficulty remembering recently learned verbal information, such as the name of someone you’ve been introduced to. Fatigue and certain medical conditions and treatments, such as cancer and chemotherapy, can also cause hazy thinking and cognitive problems.

More and more research is being undertaken to better understand brain fog, a term that’s almost as vague as brain fog itself. Read on to learn more.

Brain fog isn’t something doctors diagnose their patients with.

Dr. Pudumjee says that brain fog manifests as “cognitive inefficiencies” — meaning, you’re having a tough time calling up your cognitive resources as well as you did in the past.

You may notice difficulty with:

Attention
Concentration
Learning
Short-term memory

What that might look like can differ between people, but here are some things you may experience as a consequence of brain fog, according to Pudumjee and Danielle Wilhour, MD, an assistant professor of neurology at the University of Colorado School of Medicine in Denver.

You struggle with multitasking.
You have more trouble grasping concepts or learning than you did before.
Words arrive at the tip of your tongue, but you can’t seem to find them.
You may feel as if you’re in a dream or trancelike state.
You walk into a room and can’t remember what task you set out to accomplish.
You forget details of conversations.
You can’t absorb content as well as you used to.
You’re easily pulled off task or distracted.

Pudumjee also says that patients describe a general feeling of cognitive sluggishness. In one study that examined the use of the term “brain fog” in Reddit posts, people described this experience with a range of descriptors, including “dissociation, fatigue, forgetfulness, and excessive cognitive effort.”

These symptoms can all combine to give you the feeling that your thinking is cloudy.

One of the challenges with understanding brain fog is that there are so many potential causes, and the term "brain fog" alone doesn’t tell doctors what exactly is going on. That said, here are a few common causes to consider.

Hormonal Changes

Menopause and pregnancy can both contribute to brain fog, says Dr. Wilhour. Research shows that people who are pregnant report confusion, disorientation, and fogginess, which lead to behaviors such as putting things down in odd places, misplacing belongings, and forgetting simple work tasks. (Some call this “pregnancy brain.”)

As for menopause, one study explains that difficulty with memory can begin early on in menopause and end in postmenopause, likely because of the effects that estrogen has on memory performance.

Diet Challenges

If you’re eating a restricted diet, not consuming adequate vitamins and minerals may result in some brain fog, says Pudumjee. Specifically, a deficiency in B12 or iron can cause anemia, which can decrease your energy levels and tangentially affect cognition, says Wilhour.

In addition, food allergies and sensitivities may change your cognitive capabilities, Wilhour notes. According to a survey conducted by Beyond Celiac, an advocacy and research organization for celiac disease, 95 percent of people with nonceliac gluten sensitivity report having brain fog.

Medications

Certain medications may cause brain fog as a side effect. For example, topiramate (Topamax), which is sometimes used to treat migraine (though it’s more commonly used to prevent seizures), can leave you feeling mentally murky. “I warn patients that it can cause cloudy thinking, confusion, and word-finding difficulty,” Wilhour says.

In addition, multiple medications — also called polypharmacy — can be another factor in brain fog, she says. People experience side effects in different ways, but if you’ve noticed brain fog after starting a new drug, ask your doctor or pharmacist if cognitive issues are a possible side effect. (Don’t stop taking prescribed meditation without first consulting your physician.)

Chronic use of alprazolam (Xanax) and diazepam (Valium), taken for anxiety, can cause brain fog when used for a long time. Even if you used to be fine with it, the older you get the harder it is to metabolize.

Chemotherapy

“Chemo brain” is a well-known phenomenon that describes thinking problems before, during, and after cancer treatment, according to the National Cancer Institute.

This mental fog can be caused by the cancer itself, conditions caused by cancer (such as depression or sleep problems), or a variety of treatments including chemotherapy, radiation, and hormone therapy.

Certain Medical Conditions

Wilhour notes that brain fog may emerge with many medical conditions, including postural orthostatic tachycardia syndrome, anemia, diabetes, depression, anxiety, and autoimmune conditions such as multiple sclerosis, chronic fatigue syndrome, celiac disease, and lupus.

One common disease associated with cognitive troubles: hypothyroidism, or an underactive thyroid, which affects 5 percent of Americans older than 12.

Fatigue, depression, and difficulty with memory and executive function are often an early sign of hypothyroidism, according to research.

COVID-19

COVID-19 is known to cause lingering problems with attention, concentration, and memory after infection, according to the National Institutes of Health (NIH).

This may be due to inflammation in the brain that affects how brain cells behave, according to NIH-supported research.

In one study, 7.2 percent of people who reported having long COVID experienced brain fog, and this symptom was more common in women, those who had preexisting respiratory problems, and those who had a more severe case of COVID-19.

Mild cognitive impairment (MCI), an early stage of memory loss, isn’t the same as brain fog. According to the National Institute on Aging, roughly 10 to 20 percent of people 65 and older with MCI develop dementia over a yearlong period, however, studies are underway that aim to understand why some people with MCI progress to dementia and others don’t.

What distinguishes MCI from brain fog? The cognitive impairment that can lead to dementia affects more than memory and involves functional and behavioral changes.

Difficulty with money management when you were previously on top of financial matters, or a failure to register social norms when you previously understood them, can be early signs of dementia, as can trouble with procedures, an inability to do things you used to do, and problems with spatial awareness, such as getting lost.

MCI may proceed to dementia, but brain fog isn’t known to.

If brain fog persists past a couple of weeks, talk to your doctor, Pudumjee advises. Brain fog can be normal, especially if you’re stretched thin. But if it begins to affect your quality of life, you should seek professional medical guidance, adds Wilhour.

Your doctor will take a medical history and (possibly) do blood work, as well as ask you questions about your lifestyle to examine your habits around physical activity, diet, stress management, and sleep. To treat brain fog, it’s important to address any existing underlying medical conditions that may impact your cognitive function.

Beyond that, these expert-recommended lifestyle tweaks may help you beat brain fog.

Exercise Regularly

Stay active and aim for 150 minutes of moderate-intensity physical activity per week, if you’re healthy. (Walking counts.) “Exercise activates the brain but also tires you out, helping you sleep better at night,” says Pudumjee.

Sleep Well

Aim for at least seven hours of sleep per night, says Wilhour. And maintain a consistent rest schedule. “Go to bed and wake up at the same time,” she advises. You might want to stay up late to get more done, but it will pay off to put the laptop away or turn off Netflix. “In general, you won’t be as efficient the following day,” says Wilhour. “Sleep should be a priority for everyone.”

Manage Your Stress

Pick your favorite stress-management strategy. For instance, you could take morning walks with your neighbor, hike in nature on the weekends, practice your breathing, download books to read for pleasure, pick up a new hobby, or watch reruns of your favorite sitcom. You might also consider taking longer breaks and more vacation, as research suggests these tactics may improve focus and well-being.

“We have a primitive brain and a more advanced brain. When in a state of chronic stress, the primitive brain takes over, and we can’t use our higher thinking functions as well,” explains Wilhour. Getting a handle on stress will help you stay more in the thinking brain.

Try Cognitive Therapies

The meditative practice of mindfulness — focusing on one thing and being present — has been associated with stress reduction, decreased depression, and relief for menopausal symptoms, all of which can contribute to brain fog.

Activities that exercise your brain — reading books, doing crossword puzzles, playing games or instruments — can stimulate and support cognitive health and may help you manage brain fog.

Take Nutrition and Diet Into Account

Inflammation is thought to be related to brain fog, and an anti-inflammatory diet might counteract inflammatory effects in the body. This means limiting or avoiding highly processed foods and red and processed meats, and following a plant-based or Mediterranean-style diet centered on whole grains, fruits, and vegetables loaded with antioxidants, and healthy fats like omega-3 fatty acids.

Moderate Caffeine and Alcohol

It’s up to you if you want to include caffeine or alcohol in your life. But it’s also important to pay attention to how much and when you choose to drink these beverages. Caffeinated coffee intake is associated with a reduced risk of cognitive decline and Parkinson’s disease, according to research.

But caffeinating too late in the day can cut into your sleep, says Wilhour.

If you drink alcohol, stick with moderate consumption. The Centers for Disease Control and Prevention (CDC) recommends that women drink no more than one drink per day and men have no more than two drinks per day.

“More than that can be detrimental to brain health,” says Wilhour. Drinking alcohol before bed can also affect your sleep quality; research shows that those who drink alcohol get less sleep.

Stay Connected

“We’ve evolved to be social creatures. Living an isolated life is not what the brain is meant to do,” says Wilhour. Disconnection can also contribute to depression, which can lead to brain fog, she says. One study on more than 66,000 people found that those who were most mentally fit had a combination of social connection and social engagement (versus just one or the other).

Make sure to focus on your friendships and spend quality time with people you love on a regular basis.

Brain fog — that fuzzy, foggy feeling when you’re not at your sharpest — isn’t a medical term but researchers are increasingly trying to better understand it. Factors like stress, hormonal changes, diet, sleep, and some medical conditions and medications can lead to this temporary cognitive state. If you’re struggling and feeling mentally sluggish, there are ways to manage it with lifestyle changes and other therapies.

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