What Causes Brain Fog? Plus the Best Brain Fog Treatment and Natural Remedies

Woman experiencing brain fog

We’re all familiar with feeling “out of it” sometimes. It’s part of being a person, especially in our distraction-filled, fast-paced digital world. But sometimes that feeling persists, settling in our minds and making it hard for us to accomplish anything at all. Yes, brain fog is very real, and very unpleasant, and, unfortunately, a little tricky to get to the root of. This guide is here to help. Read on to learn the definition of brain fog, what causes brain fog, plus brain fog treatment and natural remedies for brain fog.  

You can also listen to an audio version of this guide on The WellBe Podcast. 

What’s the Actual Definition of Brain Fog?

First, let’s get to what we’re talking about when we say brain fog. We all have moments where our minds wander and we fall into a daze, or we get lost scrolling through our phones and forget why we picked the dang thing up in the first place. That’s not brain fog — that’s being a person in 2021. 

The definition of brain fog is slippery, because brain fog itself isn’t an actual condition. Rather, it’s a term used to describe a set of symptoms that are caused by any number of different factors or medical conditions. 

Someone experiencing brain fog may feel some or all of these symptoms:

  • Difficulty concentrating 
  • Not being able to think clearly/having “fuzzy” thinking
  • Memory lapses/forgetfulness
  • Inability to focus on any one thing
  • Not feeling like yourself
  • Fatigue/tiredness

To be honest, the real definition of brain fog is contained in the name itself: your brain feels foggy. It’s a pretty simple phenomenon to understand — but understanding why it’s happening and how to fix it? That’s a bit trickier.

What Causes Brain Fog? 

As we explained, brain fog is not a condition itself, but rather a cluster of symptoms that can be caused by a variety of different things — meaning there’s no single answer to what causes brain fog, but rather a whole list of potential causes. The bad news is that this list is long. The good news is that there is a list, and if you do some reflecting on your lifestyle and other symptoms, you should be able to pinpoint where your root cause lies.

If you’re experiencing brain fog, chances are that one of these is the culprit:

Inflammation: So this one isn’t really a standalone, because it’s always caused by something else (much like brain fog itself). But, because it’s such a biggie when it comes to brain function, we wanted to give it its own space. Researchers have long suspected that there’s a link between inflammation and cognitive function, and an abundance of studies have supported this belief, including multiple studies linking inflammation to cognitive diseases like dementia and Alzheimer’s. One recent study looked at brain activity in subjects experiencing inflammation compared with those who weren’t, and found that the inflammation specifically impacted the part of the brain responsible for staying alert. This means that when you’re experiencing inflammation, it’s much harder to remain mentally engaged, leading to brain fog. Inflammation can be caused by many different things, several of which we dive into below, but you can learn more about inflammation causes and how to keep inflammation down in this guide

Diet: If you have any food allergies or sensitivities that you don’t know about, you could inadvertently be triggering an inflammatory response when you eat them. This inflammation, in turn, can lead to the brain fog we explained above. Diet could also come into play if you have vitamin deficiencies, especially vitamin B12, which is essential for healthy brain and nervous system function. Vegetarians and older people are at a higher risk for vitamin B12 deficiencies, since most food-based B12 is found in meat, eggs, and dairy products, and because it gets harder to absorb B12 as you age. A vitamin D deficiency could also be the problem, since decreased levels of the vitamin are associated with impaired cognitive function

Poor Sleep: It’s not breaking news that if you’re sleep-deprived, it’s difficult to focus. But even if you think you’re getting enough sleep in terms of quantity, the quality of your sleep could be behind your brain fog. For instance, if you’re exposed to blue light close to bedtime, you might not be getting enough REM sleep, which is essential for consolidating and processing memories. You may also have a sleep disorder, like sleep apnea, which prevents you from properly resting even if you think you’re out for a full eight hours. Timing also matters, since your brain and body detoxify the most between the hours or 10pm and 2am, so if you’re awake during some or all of this time, you’re not giving your brain adequate rest. 

Stress: Chronic stress has been consistently linked to poor cognitive function over the long-term. This could be for a few different reasons, including that stress triggers inflammation and disrupts your sleep. Stress also puts your body into fight-or-flight mode, releasing the hormones adrenaline and cortisol, which tell your body to put all its energy toward the perceived “threat” and shut down other functions, like thinking clearly. This makes you unable to focus in the short-term, and can leave you mentally exhausted over time. 

Hormonal Changes: Sex hormones regulate the brain in a variety of different ways, and studies show that changes in levels of estrogen, progesterone, FSH, or luteinizing hormones can all impact your brain function. Most of the research here is centered around menopause, when women experience a huge drop in estrogen. One study found that 60% of menopausal women have difficulty concentrating, while another showed that women have difficulty focusing, recalling words, and remembering things in the period immediately before and during menopause. Of course, hormonal changes can happen at many other moments in life, like during pregnancy or if you take birth control.  

Heavy Metal Toxicity & Pollution: Various pollutants and toxins in the environment can lead to brain fog. Air pollution can cause brain inflammation, and research shows that chronic exposure to traffic-related pollution can increase the risk of neurological disorders, and that even short-term exposure to these pollutants can lower the academic performance of schoolchildren. Long-term exposure to heavy metals — like lead, arsenic, mercury, and aluminum — can also lead to neurological issues like brain fog. Since these metals bioaccumulate, it means that lifetime exposure matters, so even a little bit here and there can add up. Mold toxins can also accumulate in the body, and can lead to brain fog in some people. Only about 25% of the population is susceptible to mold toxicity, so even if nobody else in your household is experiencing symptoms, you might have a mold issue in your home. 

Certain Medications: A class of medications called anticholinergics could be behind brain fog. These drugs block the effects of a neurotransmitter that’s responsible for activity in the brain, resulting in confusion and mental fuzziness. A whole bunch of different medications fall under the anticholinergic umbrella, including drugs used to treat COPD, depression, and overactive bladder, as well as Benadryl and other allergy medications that contain diphenhydramine. And it probably goes without saying that any medication that has a sedative effect can make it more difficult to think straight. 

All of the above lifestyle or environmental factors could be contributing to or causing brain fog. But if you’ve considered all of these potential sources and crossed them off the list, the issue may be an underlying condition. 

Underlying Conditions Associated with Brain Fog

Brain fog can be a symptom of a lot of different conditions, many of which can go undiagnosed for quite a while. If you’re experiencing brain fog and can’t seem to figure out why, you might be unknowingly dealing with an underlying condition.

Stealth infections:

Harmful microbes in the form of viruses, fungi, or bad bacteria can contribute to brain fog:

COVID-19: We’re not trying to freak anyone out here, but it’s worth mentioning that some people who contract COVID report feeling fuzzy headed and unable to think clearly, both while they had the virus and in the recovery period afterward. Recently, scientists were able to pinpoint exactly why that happens by looking at autopsies of people who had died from COVID-19. They found cells called megakaryocytes, which normally live only in bone marrow, in the brain capillaries of these patients. These cells are far larger than the type of cells found in a healthy brain, and so, as one researcher put it, “finding megakaryocytes in these tubes is like finding a football stuffed into a really small pipe in your house. Nothing is going to go through.” 

Lyme Disease: People with Lyme commonly report poor memory, slower thinking, and difficulty recalling words. This is likely because it is an inflammatory disease, and when Lyme pathogens cross the blood-brain barrier, inflammation occurs in the central nervous system (where the brain lives). A study from Johns Hopkins that looked at brain scans of people with chronic Lyme disease found that they all had a chemical marker for brain inflammation, as compared with a control group that did not have that marker. 

Small Intestinal Bacterial Overgrowth (SIBO): Many people with SIBO also report having brain fog, and research has consistently shown a link between the two. This is likely because SIBO means you have too much bacteria (both good and bad) in your small intestine, and these bacteria produce the chemical histamine in order to break down food. But since there’s too much bacteria, there’s also too much histamine, and excess histamine in the gut means excess histamine in the brain, where it can lead to brain fog. 

Autoimmune and other underlying conditions:

These causes can be genetic, or caused by lifestyle or environmental factors.

Celiac Disease: As we mentioned above, a food intolerance can cause inflammation that leads to brain fog. Celiac disease is an extreme example of that, with some additional factors that can lead to cognitive impairment. First there’s the chronic inflammation from your body attacking healthy cells, and then there’s the fact that celiac disease damages the gut and, when left untreated, can make it impossible for a person to absorb nutrients. This in turn leads to micronutrient deficiency, depleting the brain of vital compounds it needs to function correctly. 

Anemia: As we mentioned above, being deficient in vitamin B12 can lead to brain fog. But if you’re really deficient, you can also develop anemia, a condition where you don’t have enough red blood cells. Anemia is associated with low iron levels, since 70% of the body’s iron is found in red blood cells, and low iron can cause symptoms like fatigue, depression, and brain fog.   

Diabetes: If you have untreated diabetes, then your insulin levels are out of whack. This matters for your brain because insulin regulates blood sugar, and blood sugar is your brain’s primary source of fuel — so not enough blood sugar means your brain has no fuel. Too much  blood sugar, on the other hand, can increase serotonin and neurotransmitters in the brain, and while these neurotransmitters normally have a positive effect on brain function, too much can have the opposite effect. 

Hypothyroidism: When your thyroid gland is underactive, it doesn’t produce enough thyroid hormones. Two of these hormones, T4 and T3, are critical to many body functions, including brain function. So when these hormone levels drop, they can make your brain more sluggish

Lupus: Lupus is an autoimmune disease where your immune system attacks your bones, joints, and internal organs, and “lupus fog” is a common symptom. Though it’s tough to pin down exactly why this cognitive impairment happens, it’s likely a side effect of the fatigue, stress, and depression that accompanies dealing with the disease. In rare cases, lupus can actually do damage to brain cells, which leads directly to difficulty thinking. 

Multiple Sclerosis (MS): More than half of the people who have MS will develop cognitive issues. MS affects the nervous system, preventing your brain from sending information to the rest of your body the way that it normally does. This can lead to difficulty concentrating, focusing, or even speaking. 

Chronic Fatigue Syndrome (CFS): CFS is a poorly understood condition that causes severe, ongoing fatigue, which can negatively impact the brain’s ability to function. Researchers at Stanford recently found that people diagnosed with CFS had reduced levels of a certain type of brain activity, called “peak-alpha frequency,” which is associated with cognitive performance. The study also found that CFS patients have excessive delta waves, which are typically associated with sleep, while they’re awake. This means that their brain is, almost literally, half asleep, and is functioning at a reduced speed.

Fibromyalgia: Fibromyalgia is a disorder characterized by widespread musculoskeletal pain accompanied by fatigue, sleep, memory and mood issues. Researchers believe that fibromyalgia amplifies painful sensations by affecting the way your brain and spinal cord process signals. Since brain function is compromised, it’s no surprise that  “fibro-fog” is one of the primary symptoms. 

Natural Approaches to Brain Fog Treatment 

Just as what causes brain fog has a lot of different potential answers, there are also a lot of different potential remedies for brain fog. Ultimately, the brain fog treatment that works for you will depend on the root cause that you’re addressing, which means that there’s no single approach that will work for everyone. 

This means that the first step in figuring out the right brain fog treatment for you is to determine what’s causing it. Depending on what’s going on with you, just reading through the potential causes above might be enough for you to identify the issue. In other cases, you may need to enlist the help of a professional. 

If you’re struggling with brain fog and don’t know why, the best first step is to find an integrative healthcare practitioner who can do proper testing on you. By looking at your bloodwork and listening to all of your symptoms, the practitioner can determine if you have an underlying condition, an infection, nutritional deficiencies, or any other abnormal levels that indicate what’s amiss. Once you know what’s going on, it’s easier to narrow down the best brain fog treatment for you.

But if you’ve seen someone and are still unsure why you’re experiencing brain fog, chances are it has something to do with chronic inflammation (whether that’s being caused by heavy metals, a bacterial infection, your diet, etc.). The good news is that there are a number of lifestyle-related changes you can make that will help to reduce chronic inflammation no matter what the actual root cause, and therefore may reduce or eliminate your brain fog. What’s great is that these remedies for brain fog are free of any side effects, and are healthy choices for anybody, regardless of whether or not they’re experiencing fuzzy thinking.

Try these natural remedies for brain fog:

  • Eat well. If we’ve said it once we’ve said it a thousand times, but we’ll say it again: what you put in your mouth is your first line of defense against any health issues. We can’t overstate how important diet is to your body’s ability to function, and this includes your brain (it’s a muscle, after all!). Eat mostly whole foods, avoiding inflammatory items like processed foods and sugar as much as possible, and make sure to get in lots of healthy fats, omega-3 fatty acids, and anti-inflammatory foods to fuel your brain. 
  • Get enough sleep. Make sure you arrange your schedule so that you can get 7-9 hours of sleep per night. Read more about how to get the right amount of sleep for your body
  • Manage your stress. If you’re feeling chronically stressed, take steps to manage and reduce stress in your life. This might mean removing some of the stressful elements, prioritizing self-care, incorporating a mindfulness or meditation practice, or all of these things!
  • Exercise regularly. Staying active has been associated with sharper mental acuity and better memory. That’s because exercise releases cytokines (chemical messengers) and endorphins (the happy-making hormone), both of which rejuvenate the brain. 
  • Take the right supplements. Most of us should be taking a vitamin D supplement anyway, and its association with brain function is just further evidence of that. Add a B-complex vitamin to the mix as well to make sure you’re not deficient in B12. For a full list of fully vetted, WellBe-approved supplements, check out our Non-Toxic Product Database
  • Do an elimination diet. If you think a food sensitivity might be causing your brain fog, try an elimination diet where you cut out common food allergens (like gluten, dairy, soy, etc) and vices like alcohol, caffeine, cigarettes, etc. Then slowly reintroduce them into your diet, noticing how you feel after each. You may find that one or more were causing you chronic inflammation and contributing to your brain fog!
  • Try intermittent fasting. Intermittent fasting has a ton of benefits (read all about the science of IF and how to get started in our interview with Dr. Amy Shah!), and one of them is improved brain function. Multiple studies have found that regularly practicing intermittent fasting boosts cognitive performance.
  • Invest in an air filter. If you think air pollution might be a contributing factor to your brain fog, get a high quality air filter or air purifier for your home. While you can’t control the quality of the air outside, you spend the majority of your time in your house, so this should make a difference. For a full list of fully vetted, WellBe-approved air filters and purifiers, check out our Non-Toxic Product Database

While not all of these remedies for brain fog will work for every person (because every person’s underlying issue is unique), all of them are best practices for keeping a healthy mind and body in general. If you implement all of the strategies above and are still struggling with brain fog, seek out a doctor to get to the root issue. The best brain fog treatment will become clear from there.

The WellBe Takeaway: Clearing Up the Fog on Brain Fog

Brain fog is, well, a fuzzy issue. The term gets thrown around a lot, but there’s not a lot of clarity on what it means, what causes brain fog, and how to deal with it. Here’s what to remember about brain fog and your health:

  • Brain fog is not a medical condition in itself, but rather a set of symptoms caused by something else. Because of this, the definition of brain fog is limited to the symptoms it causes, which include difficulty concentrating or thinking clearly, memory lapses, and an inability to focus.
  • There are a number of lifestyle- and environment-based factors that could be causing brain fog. These include: inflammation, diet, poor sleep, stress, stealth infections, certain medications, heavy metal toxicity & pollution, and hormonal changes.
  • Sometimes, an underlying condition is the cause of brain fog. Conditions that can cause brain fog include: COVID-19, celiac disease, Lyme disease, diabetes, anemia, lupus, multiple sclerosis, hypothyroidism, SIBO, chronic fatigue syndrome, and fibromyalgia. Remember that most of these conditions have the same lifestyle- and environment-based root causes and contributing factors that we addressed above.
  • If you’re dealing with brain fog, it’s best to figure out the underlying cause before you can settle on a brain fog treatment. Often, the first step is to see an integrative practitioner who can listen to your symptoms and do blood work. They can test to see if you have any nutritional deficiencies, if your levels are off in any way, or if there’s some underlying condition. 
  • If your labs don’t show anything or you can’t see an integrative health professional, there are various lifestyle changes you can make that may clear up your brain fog. Which one works for you will depend on the original cause, but each of these strategies is also great for health overall. Natural remedies for brain fog include: eating a healthy, whole food-based diet; getting enough sleep; managing your stress; exercising regularly; trying intermittent fasting; taking vitamin B12 and vitamin D supplements; doing an elimination diet to suss out any food sensitivities and diet-based causes of inflammation; and installing an air filter or air purifier in your home.  

Have you ever struggled with brain fog? How did you (or do you) treat it? Share your experience in the comments below!

You can also listen to an audio version of this guide on The WellBe Podcast. 


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3. Kennedy, David O. “B Vitamins and the Brain: Mechanisms, Dose and Efficacy–A Review.” Nutrients vol. 8,2 68. 27 Jan. 2016.

4. Anjum, Ibrar et al. “The Role of Vitamin D in Brain Health: A Mini Literature Review.” Cureus vol. 10,7 e2960. 10 Jul. 2018.

5. Tähkämö L, Partonen T, Pesonen AK. Systematic review of light exposure impact on human circadian rhythm. Chronobiol Int. 2019 Feb;36(2):151-170.


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