What is Brain Fog?

As a 40-something working mom of two kids, I have what you might describe as a very “full” brain. Toss some perimenopause into the mix, and some days my memory seems to short-circuit (like when I suddenly forgot the debit card PIN I’ve had for years while getting gas). Other days, my mind feels like it’s spaced-out and hazy — like my head is literally in the clouds.

Sound familiar? If so, you might also be dealing with brain fog. While brain fog isn't a medical diagnosis, it can show up as trouble focusing, memory slips, or just feeling like you're moving in slow motion. For some, brain fog happens only once in a while, like the morning after one too many merlots. Others may feel like it happens on the daily. 

Although anyone can have bouts of brain haze, women get foggy more frequently than men. That’s because we experience many of the conditions linked to brain fog more than men: hormonal changes during pregnancy and menopause, autoimmune diseases, and thyroid disorders, for example (sorry, ladies). [,2, 3]

So, what exactly is brain fog? Well, it’s different for everyone, says Hannah Holmes, Ph.D., a psychologist and a clinical assistant professor at Appalachian State University in North Carolina. It’s a collection of various cognitive-related symptoms that can include feeling like your brain is running in slo-mo, forgetting even familiar names and tasks, and having trouble focusing on chores, work, meetings—you name it.

The good news? It’s likely you can de-fog your noggin with some simple lifestyle tweaks. Here’s what you need to know.

What are the symptoms of brain fog?

What does brain fog feel like? The symptoms vary from person to person, says Saira Bhatti, M.D., a board-certified psychiatrist and psychotherapist based in New York City. But they could feel a little like this:

• It seems impossible to concentrate or stay focused at work, at home, wherever.
• You sometimes feel slightly confused or disoriented, like missing a turn when driving in a familiar place.
• You’re spacey and forget basic things, like turning on the dryer after loading it with wet laundry.
• Your brain just feels tired, like it needs to be plugged in somewhere to recharge.
• Your thinking seems to be crawling at half-speed.
• You make spur-of-moment decisions without really thinking about them—or can’t make a decision at all, like what to make for dinner.
• You have squirrel-brain and are easily distracted.
• You have trouble finding words (embarrassing example:recently I blanked for a second on the name of the “metal stabby thing” we use to spear food to put into our mouths).
• You lose your train of thought mid-sentence (wait, what was I saying?).
• You feel generally “out of it.”

The science of brain fog

The exact step-by-step process of what happens in the brain when we get brain fog isn’t totally understood, in part because there are a number of factors that can cause brain fog. Plus, there’s no “standard” brain fog: It can look and feel different to everyone. But research has found a couple of strong correlations:.

Hormonal changes

In women, many times brain fog is tied to hormones, which is why it’s such a common experience when hormones go haywire, like during pregnancy and perimenopause.  [4, 5]

Estrogen, in particular, plays a big role in cognition. The brain is full of estrogen receptors in areas that regulate mood and brain function. Estrogen has protective properties for the brain that can help shield the brain from damage and neurodegenerative diseases. It activates pathways in the brain to help brain cells grow and repair themselves. Estrogen also reduces inflammation and cell damage from oxidative stress. [6]

Inflammation

Inflammation may be a key driver of brain fog and can be caused by a number of factors. Research suggests that brain fog from long COVID may be linked to ongoing inflammation in the body and problems with the brain’s protective barrier, which can affect memory, learning, thinking, and mood. It’s thought inflammation is triggered by the immune system’s response to the COVID-19 virus. [7] Other research has also pointed to the link between cognitive impairment and inflammation in the tissue and organs (called peripheral inflammation). [8]

What’s the connection between brain fog and fatigue?

Brain fog and fatigue are “inextricably linked,” Holmes says. The brain and the body run on a feedback loop, with each informing and affecting the other. When our bodies feel wiped out, our brains feel zonked, too. The flip side of that is also true.

“When you feel physically exhausted, it is quite literally depleting the energy that your brain uses, too,” Holmes says. “So it makes sense that you would feel cognitively or mentally fatigued or foggy when you’re physically exhausted, and vice versa.”

When our bodies feel like they’re running on empty,  our nervous system  has to work harder to perform even pretty basic motor skills and mental activities. [9] When stress ramps up, so does cortisol — that stress hormone  you’ve likely heard tons about on social media lately. Cortisol preps us for “fight or flight.” When stress is sky-high for long chunks of time, that cortisol keeps on pumping, holding our  brains and bodies alert and tense. Try getting a decent night’s sleep when cortisol levels are high—not gonna happen. Eventually burnout hits, as neither the body nor the brain can sustain it.

“That burnout is often accompanied by depression or anxiety, which further fuels mental and physical exhaustion by disrupting sleep and serotonin levels,” Bhatti says. “It quickly becomes a cycle.”
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What causes brain fog?

Brain fog can pop up for all sorts of reasons — from not sleeping well, not drinking enough water, feeling stressed out, or dealing with chronic pain. In many cases, inflammation is the culprit, brought on by stress, diet, hormonal changes, health conditions, or other causes. [10]

Lifestyle causes of brain fog

• Poor sleep: This one’s a no-brainer. When we don’t get enough zzz’s, our bodies feel tired from head to toe. Research has found lack of quality sleep actually slows reaction time and impairs how well our brains work.[11]
• Dehydration: Time for more sips from that Stanley cup. Not drinking enough water can cause cortisol levels to rise. As a result, “feel-good” hormones like serotonin and dopamine plummet. Dehydration also causes an imbalance in our electrolytes, which further impacts cognitive function. [12, 13, 14, 15]
• Lack of physical activity: Need another reason to hit the gym? Your noggin needs exercise as much as the rest of your body does. In one study, too much sitting around was linked to worsening brain function – even in older adults who were otherwise highly active. [16]
• Excessive screen time: Yep, our phones are probably a problem. Marathon scrolling sessions or laptop time can strain the eyes, which makes our brains feel tired. Too much passive screen time (think: watching TikTok after TikTok after TikTok) may also lead to “digital dementia,” or increased forgetfulness. [17, 18]
• Alcohol or drug use: Alcohol and drugs directly damage the brain and can have long-term impact on memory, cognitive function, and executive reasoning. [19, 20]

Dietary causes of brain fog

• Added sugar: Consuming too much added sugar can have an impact on the brain as well as the body. Over time, sugar overload can fuel inflammation, which is thought to be a cause of brain fog. [21] The CDC recommends limiting added sugars to less than 10% of your daily calories (so, 200 calories or fewer of added sugar if you’re eating 2,000 calories a day).[22]
• Ultra-processed foods: Research has found eating overly processed foods was associated with an increased risk of cognitive impairment, while a diet composed of mainly unprocessed or minimally processed foods may lower that risk. What counts as an ultra-processed food? Many foods are processed (even frozen veggies), but ultra-processed foods tend to have lots of ingredients and additives (many of which could be found only in a lab). They’re often convenience foods that require minimal cooking or preparation. [23, 24]
• Caffeine: Ever tried to kick caffeine? Your head probably throbbed and felt like it was encased in mud. A little caffeine can make you feel alert and focused, but too much can have the opposite effect by trashing your sleep or making you feel scattered, anxious and jittery, Holmes says.
• Food allergies or intolerances: Research has found food allergies and sensitivities—like to gluten—can affect brain function and make you feel fuzzy. [25]
• Small intestine bacterial overgrowth (SIBO): SIBO is a condition in which too much bacteria grow in the small intestine, using nutrients needed for the rest of the body as fuel. In addition to gastrointestinal symptoms, SIBO can also cause brain fog. [26, 27] 
• Iron deficiency and anemia: Anemia, including iron-deficiency anemia, commonly results in fatigue and brain fog. Iron deficiency and anemia  affect women more commonly than men (thanks, menstrual periods). Iron is required to produce red blood cells, which shuttle oxygen to the brain. [28, 29]‍
• Other vitamin and mineral deficiencies: Nutrients like vitamin D, omega-3 fatty acids, vitamin B12, and magnesium help protect your brain from inflammation and oxidative stress. Not getting enough key vitamins and minerals in your diet can increase your chances of brain fog, cognitive decline, anxiety, and depression. [30, 31, 32, 33]

Medical conditions that can cause brain fog

• Hormonal changes: “The hormonal fluctuations women experience while pregnant and postpartum, combined with stress, fatigue, and sleep deprivation, create a perfect recipe for brain fog,” Bhatti says. “Similarly, hormonal changes that occur around menopause can contribute to brain fog.” [34]‍
• COVID-19: Cognitive problems, including brain fog and memory loss, are common symptoms associated with long COVID. So are fatigue, joint pain, and breathing issues.  [35, 36]‍
• Cancer: Hair loss and nausea get a lot of attention when it comes to chemotherapy side effects, but brain fog is another one. [37]‍
• Chronic pain: Known as “fibro fog,” cognitive issues often accompany fibromyalgia and other similar conditions, Holmes says. [38]‍
• Autoimmune diseases: Many autoimmune disorders can cause brain fog, including multiple sclerosis (MS), lupus, and rheumatoid arthritis. And once again, women bear the brunt, as they account for nearly 80 percent of people with autoimmune disorders. [39, 2]‍
• Thyroid disorders: Both an overactive and underactive thyroid are commonly linked to issues with memory and concentration. [40]‍
• Diabetes: Both type 1 and type 2 diabetes can lead to brain fog, caused by imbalances in blood glucose and insulin. [41]‍
• Neurological conditions: Neurological diseases, including MS, dementia, and Parkinson’s, can cause brain fog. That’s due to inflammation and changes across the brain or central nervous system. Cognitive decline is the top symptom of dementia. [42]

Mental health conditions that can cause brain fog

• Depression and anxiety: Issues with memory and concentration are commonplace with depression and anxiety, potentially due to chemical or hormonal imbalances in the brain, poor sleep, and stress. [43, 39] 
• PTSD, trauma or grief: Memory lapses, trouble with focus, and other cognitive issues are  common symptoms of trauma or post-traumatic stress disorder (PTSD). The brain even interprets grief as a form of trauma. [44, 45] 
• Chronic stress/burnout: Left untreated, long-term stress can wreak havoc on our bodies and brains. Stress is a major contributor to both burnout and brain fog, Holmes and Bhatti say. 
• ADHD/Autism Spectrum Disorder (ASD): ADHD, ASD, and brain fog symptoms often overlap. Brain function and mental processing work differently in neurodivergent people, and memory, focus, and organization are common existing challenges. The mental fatigue and brain haze that commonly result from that persistent mental strain is often more long-term than in people who don’t have ADHD or ASD. [46, 47]‍
• Traumatic brain injury (TBI): Brain fog is commonly self-reported by people who are coping with a TBI, and it can be a significant obstacle in their recovery of memory and cognitive function. Research has found people with mild, moderate, or severe TBI have higher instances of brain fog than people who don’t have a TBI. In addition, brain fog was associated with higher rates of depressive symptoms. [48]

Only a healthcare provider can give you a clear diagnosis, but these scenarios might help you distinguish three memory-related conditions: brain fog, ADHD, and dementia. [49, 50, 51, 52]

Brain Fog Behavior	ADHD Behavior	Possible Dementia Behavior
You briefly can’t recall someone’s name that you’ve met before, but then it comes back to you later.	You immediately forget a person’s name after learning it.	You can’t remember the names or faces of people close to you, like your spouse or children.
You occasionally forget where you put your keys after you get home, especially when you’re really stressed or tired.	You regularly misplace everyday items, like your keys, wallet, or phone.	You lose your keys. If you find them, they may be in a really strange place where you don’t remember putting them, like in the freezer.
You sometimes space out when driving or walking and make a wrong turn. You may temporarily forget where you parked your car.	You can get easily distracted while driving, like if you’re listening to music or talking to other passengers.	You forget simple directions to familiar places or how to find your way home when you’re out.

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How do you treat brain fog?

Brain fog is a symptom, not a diagnosable illness or condition on its own, the experts say. Still,  you should address it. “It’s a sign from your body that something is off,” Bhatti says.

Sometimes it’s as simple as going to bed a little earlier to catch a few more zzz’s at night. But if that foggy feeling hangs out no matter what, it’s probably time to chat with your healthcare provider to try to decode the root cause—like if it’s related to a physical or mental health condition.

Lifestyle changes

The good news? There are simple lifestyle hacks that may help sweep away the cobwebs.:

• Get good sleep: Full stop, sleep is definitely Step One. Aim for seven to nine hours a night to keep your body and mind running at peak performance.
• Improve your diet: Stick to whole, unprocessed foods as much as possible, including tons of fruits and veggies. They’re loaded with anti-inflammatory and brain-boosting micronutrients and antioxidants. Limit or avoid refined sugars. If you’re lacking certain micronutrients, supplements can fill the gap. The nootropic brain pick-me-ups in Fixie Dust contain key micros that may support focus, including vitamin B12 and L-theanine. 
• Move your body: Regular exercise increases blood and oxygen flow to the brain and boosts the production of endorphins, which can keep us alert and improve our moods. More focused and happier? Sign me up. [16]
• Manage your stress: Try yoga, meditation, nature walks, or breathing practices. Getting a grip on stress goes a long way to warding off the fog. 
• Stay hydrated: Our brains are mostly water, and they don’t function well when they’re thirsty. Research has shown lower hydration levels were linked to greater decline in cognitive function over two years (this is your cue to go drink a glass of water). [53]
• Train your brain: Doing puzzles, reading actual books, learning a new language or skill, or practicing fun brain games can keep your mind razor-sharp. [54]
• Limit screen time: This is especially important before bed, as blue light from our devices can mess with sleep. During the day, take regular screen breaks to give the eyes a rest.  [17, 18]‍
• Cut back on alcohol and caffeine: You’ll get better sleep and will likely be less anxious when you curb the coffee, booze, or both. [19]

Emerging treatments for brain fog

The research isn’t conclusive on the effectiveness of these therapies, but some newer treatments show promise for brain-fog relief.

• Neurofeedback: Some early research has found neurofeedback—a type of mind-body therapy that measures brain waves with an EEG and then tries to “train” them through visual or auditory feedback—improved brain fog in long COVID and cancer patients. [55] 
• Medication: Case reports have shown the combination of two existing medications—guanfacine (a medication used to lower blood pressure or manage ADHD) and the antioxidant N-acetylcysteine (NAC, available as both a prescription drug and a dietary supplement)—improved memory, attention, and processing speed. [56] It’s possible the combo could drop blood pressure too low, so it’s a good idea to check with a healthcare professional first. ‍
• Light therapy: Some small studies into photobiomodulation (PBM, or low-level light therapy) have found positive outcomes for long COVID patients with brain fog. PBM may lessen inflammation and stimulate cell growth. [57, 58]

When should you consult a doctor about your brain fog?

It can be frustrating to misplace your phone or jarring to forget a friend’s name on the spot. Usually, it’s not a cause for concern, but it may be hard to know when brain fog is worrisome. 

It’s common for memory and concentration to get less sharp as we age. Our memory actually peaks in our 30s and then starts to dwindle as we get older.  But as you approach your 50s, it might be time to pay closer attention to whether those foggy moments are getting more frequent or more severe. [50]

Regardless of your age, if your brain fog is ever accompanied by physical symptoms, like a headache or chest pain, get medical attention right away, Bhatti says. You should also call your healthcare provider if you have a very sudden and severe bout of forgetfulness, she adds, like getting lost in a normally familiar place or being unable to remember your own name. Those symptoms  go beyond just run-of-the-mill, basic brain fog.

Are you feeling foggier more often than not? “Brain fog is concerning when it begins to significantly interfere with day-to-day life or is starting to produce significant consequences,” Bhatti says.

Want to know more about what’s going on inside your head? These lab tests are standard in diagnosing the root of memory and cognition changes. ^[59]
Ask your doctor about:

• Complete blood count (CBC)
• Comprehensive metabolic panel (CMP)
• Vitamin and mineral deficiencies
• Thyroid stimulating hormone (TSH)
• Other tests as needed, including MRI or CT scans and neuropsychological testing

Ask yourself these questions to assess how much impact your brain fog is having on you:

• Are you missing deadlines at work?
• Are you struggling to get through your to-do list? 
• Are you forgetting plans with friends or family? 
• Are you feeling so scattered or spacey that you’re late to work, school pick-up, or other appointments?
• Are you having trouble keeping up with daily tasks?
• Is your fogginess or forgetfulness affecting your work and relationships? 

And consider asking others, too. “A good gauge is asking if those around you have noticed any changes or have concerns—loved ones, friends, coworkers,” Bhatti adds.

The bottom line

Brain fog is a common collection of various symptoms, including forgetfulness and mental fatigue. It’s very common, particularly among women, but it can feel different for everyone. 

Brain fog isn’t a diagnosis by itself, like the flu or diabetes; it’s a symptom of other conditions or lifestyle factors. Some treatments and lifestyle tweaks may be able to make brain fog feel less severe and less frequent, or even get rid of it altogether, but it’s important to determine the root cause of the brain fog first. Once you’ve uncovered the root of your foggy noggin and clear the cause, you just may be surprised by how quickly your mental sharpness returns.

Key takeaways

• Brain fog feels different for everyone, but it’s typically characterized by forgetfulness, slowness in finding or processing words, and trouble focusing or concentrating.
• Brain fog has a variety of lifestyle, medical, and mental causes, including chronic illness or pain, stress, long COVID, hormonal changes, poor sleep, depression, anxiety, dehydration, and diabetes.
• Brain fog is a symptom of other conditions or issues, not a diagnosis. To fix it for good, you have to first figure out what’s causing it.
• There are lots of natural treatments and lifestyle changes to help with brain fog, including getting plenty of sleep, staying hydrated, managing stress, exercising regularly, and addressing any vitamin or mineral deficiencies in your diet.