You need to stop by the grocery on the way home from work for two gotta-have items. One of the items is coffee, but you can’t think of the other one to save your life.

Every time you sit down to do that report for work, you can’t seem to focus and make any real progress.

Better wait to walk to the end of the driveway to get the mail because your neighbor, that you’ve only lived beside for five years, is in his yard, and you don’t remember his name.  You know you know it, but your brain can’t seem to reach it.  

Sound familiar?

Even though you may feel like you’re losing your mind, it could just be a bit of brain fog. Thankfully, you can take steps to clear up the haze after you figure out what’s causing it.

What Is Brain Fog?

Brain fog is not a medically recognized term or diagnosable condition. It’s a common phrase used for a myriad of symptoms affecting your ability to think. Brain fog can include things like memory problems, lack of mental clarity, and an inability to focus, and put thoughts into words. Some people describe it as mental fatigue.

You know – the kind of mental exhaustion where you tell yourself if you can just make it to the weekend, you’ll get some rest. That should help. Next week will be easier. The problem is that when the weekend rolls around, there are a gazillion more things to do and stress about. So, you end up not getting the much-needed rest. Or if you do, it doesn’t seem to help the problem in the slightest.

That’s because to resolve brain fog, you have to figure out and address what’s causing it. 

On a cellular level, brain fog is believed to be associated with high levels inflammation and changes to three primary hormones: dopamine, serotonin, and cortisol. One theory behind the underlying reason for brain fog symptoms is that higher levels of inflammatory molecules, including adipocytokines and histamines, stimulate microglia activation.

Five Common Causes of Brain Fog

According to one study, the most commonly reported brain fog triggers were fatigue, lack of sleep, prolonged periods of standing, dehydration and feeling faint. Sometimes, a trigger can’t be avoided. However, if brain fog is an ongoing issue for you, taking a look at and adjusting your lifestyle habits might be warranted.  Let’s look at some common causes:


In the short-term, stress can make you irritable, anxious,  distracted and forgetful. Over time, elevated levels of cortisol, the stress hormone, can chip away at your physical, mental and emotional healthChronic stress actually damages your brain.  Stress shrinks dendrites, kills neurons, and prevents new cell growth in the hippocampus – essential to memory. While it’s doing all that, it causes your amygdala, the fear and emotional center of the brain, to increase size and activity. This makes it harder for your brain to learn new information and remember it.

Lack of sleep

Sleep deprivation can have serious short-term and long-term consequences for your overall and brain health. After just one night of skimping on sleep, the results can be seen in delayed reaction times, glucose levels, mood, headache, impaired memory, and hormone balances. Recent research shows that not getting enough sleep may even shrink your brain. You’ll want to aim for eight to nine hours of sleep per night. But don’t forget, quality matters too.


Diet can also play a role in brain fog. When it comes to your brain, you literally are what you eat. What goes into your mouth has everything to do with what goes on in your head. You have a “second brain,” the enteric nervous system, in your gut which communicates with the brain in your head.

To get the most brainpower out of your diet, you will want to include fatty fishes, foods with probiotics, whole grains, leafy greens and lots of lean protein. If you’re missing essential vitamins and minerals, your brain function will reflect it. For example, a vitamin B-12 deficiency can bring about brain fog.

Also, food allergies and sensitivities can make your thinking fuzzy. The most common culprits are:

  • Processed meat (sodium nitrates)
  • Dairy
  • MSG
  • Alcohol
  • Artificial sweeteners

Dehydration can also contribute to sluggish thinking.

Hormonal Changes

Hormonal changes can also trigger brain fog. The brain and entire body rely on a complex symphony of hormones that work to keep one another in check. So, when levels of one hormone fall too low or climb too high, your whole system, including brain function, can be thrown off.

For example, levels of the hormones progesterone and estrogen increase drastically during pregnancy. This change can affect memory and cause short-term cognitive impairment. Similarly, a drop in estrogen level during menopause can cause forgetfulness, poor concentration, and cloudy thinking.

Medications and Medical Conditions

Brain fog is a common side effect of many drugs. If you notice symptoms upon taking a medication, talk with your doctor. Lowering your dosage or switching to another drug may alleviate the problem. Brain fog is a well-known side effect of chemo and is referred to as chemo brain.

Medical conditions associated with inflammation, fatigue, or changes in blood glucose level can also be the cause of mental fatigue. For example, brain fog is a symptom of

  • chronic fatigue syndrome
  • fibromyalgia
  • anemia
  • depression
  • diabetes
  • hypothyroidism
  • autoimmune diseases such as lupus, arthritis, and multiple sclerosis

Diagnosis and Treatment of Brain Fog

No matter what you think is causing your brain fog, it’d be a good idea to get checked out by your doctor. However, there isn’t one test specifically for the condition. When you get to your doctor’s appointment, you can expect to have a regular physical examination with some follow-up questions.

Your doctor may feel additional blood work is necessary to rule out the brain fog being a symptom of a more serious issue. Blood work can identify the basic health markers, glucose levels, nutritional deficiencies, organ function, hydration, and more.

Your doctor can then suggest possible solutions to implement based on the exam, questions, and tests. Treatments are different depending on the determined cause. Your physician may advise you to get more sleep, switch medications,  start taking nutritional supplements, or something else. You may need to try out different treatments before you find one that works for you.


Brain fog is an annoying symptom that can arise for a wide variety of reasons. It may feel like you’re going to be stuck in that sleepy mindset forever, but there are plenty of ways to wake your brain up. Try out different treatments until you find one that works. Then, make adjustments as necessary to prevent the condition from returning. One day, you’ll clear away the fog, and the sun will shine again! 

Contributing Author

Kayla Matthews writes about wellness, productivity and stress in the modern world for websites like MakeUseOf, BioMed Central, and The Huffington Post. To read more posts from Kayla, subscribe to her blog, Productivity Theory.

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  1. Excellent article, Kayla! Of late, I’ve been feeling a little fatigue and am putting it down to the heat where I live. Of course, being diabetic does not help. I am trying to get enough sleep (another of my culprits) so that the following day doesn’t go down the drain. The lack of sleep can cause havoc! The diet info is interesting–never thought of that as a cause for brain fog. Thank you!.

    Thank you Debbie!

  2. I’ve taken care of diet and sleep (yes, what you eat affects every aspect of you, especially your brain). My issues are hormones (pre-menopause) and stress. I also think that “smart” phones are a big contributor as they train us to have shorter and shorter attention spans and prevent us from thinking deeply or simply being.

    • Hormones can play havoc with the female brain. I know what you mean about the phones and short attention spans. It’s really a problem!

  3. Wow that is amazing I am fortunate don’t get brain fog. really careful with diet and sleep . also drink alkaline water helps

  4. elle sommer Reply

    Sugar is the culprit for me with brain fog. So I understand the connection . between it a foggy brain and food. And I think sometimes it’s plain old lack of paying attention or mindlessness…at least for me. Fascinating article Kayla.

  5. This is an excellent article Kayla. Brain fog gets me during my hormonal bursts. I have no choice but to ride it out and literally go for a long hard power walk.
    xoxo, Z~

  6. I am definitely subject to brain fog, and am so grateful for this information. I agree, you need to address the underlying causes, which can sometimes be complex if you have an invisible illness. I find the link with histamines interesting as I don’t process them as efficiently as the average person.

    • You are smart to pinpoint the cause for you. Allergies was actually a big cause when researching – just not as big as some of the others.

  7. When I have brain foggy days, I found that Transcendental Meditation (TM) helps tremendously. The meditation session is usually an unscheduled one (beyond the 2 recommended) and extended beyond the 20 minute routine. When I open my eyes, sometimes after 45 minutes, it is like I had a shot of caffeine in my brain! I do not fall asleep at all and the benefits of the meditation seem like “dep brain work” for me. Just thought I would pass this on to all of you. I am 66 years old and am a psychotherapist in private practice. I recommend TM to all my clients but surprisingly enough, very few actually follow through and do it. If only they knew the positive addiction they are missing out on! 😉

    • Thanks for sharing your experience, David. I do believe meditation can make everything better. There is solid scientific evidence as to why it would help brain fog! Glad it does. 🙂

  8. I totally went through brain fog while writing a dissertation. I was very sleep-deprived and found (and stressed) and found it affecting my speech and memory.

    • So you know this to be true firsthand! Hopefully, it resolved when you were able to change your lifestyle habits when the dissertation was finished. You are in Wilmington? I’m in Greensboro! 🙂

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