Brain Fog: When It’s Normal and When to See a Doctor

Have you ever experienced that fuzzy feeling in your head after an especially stressful day or after not getting enough sleep at night? Odds are, you… Samantha Davis - November 29, 2022

Have you ever experienced that fuzzy feeling in your head after an especially stressful day or after not getting enough sleep at night? Odds are, you were experiencing brain fog, a medical term that encompasses brain symptoms like lack of focus, poor memory, and difficulty making decisions. While brain fog is normal when it happens occasionally, frequent brain fog could indicate anything from too much stress to serious underlying conditions like dementia. Sudden-onset brain fog could indicate a stroke. Below, we’ll take a look at the causes of brain fog and when you should see a doctor.

Too much stress makes it impossible to think clearly. Medical News Today.

Stress is a Silent Killer

Stress wreaks havoc on your entire body. It disturbs sleep cycles, messes with your metabolism, weakens your immune system, and causes mental cloudiness. This happens because stress causes cortisol to rush through your body, disrupting its normal processes and focusing all its efforts on the perceived threat. Stress causes brain fog because it triggers inflammation in the brain. Any type of swelling in the brain narrows neural pathways. These pathways are where neurons travel back and forth to pass information between your body and brain. With these pathways being narrowed, processing information takes longer and thinking comes a little slower.

Conditions like sleep apnea stop you from feeling fully rested after sleep. Shutterstock.

Poor Sleep Habits Disrupt Your Day

Poor sleep habits (or sleep hygiene) make it impossible for the brain to work effectively at night. For the brain to do things like store information and remove toxic waste, you need to reach the REM cycle of sleep. This toxic waste builds up over time and causes side effects like poor memory and decision-making. Conditions like sleep apnea can also disrupt your ability to get a full night’s sleep, especially if you’re tired but don’t remember waking up. Sleep apnea can be dangerous and possibly fatal if left untreated.

Covid-19 causes brain fog months after getting better. Stanford Medicine.

Covid-19 Causes Brain Fog Months Later

The world is still recovering from all the challenges that came along with the Covid-19 pandemic that started in March of 2020. As it turns out, not everyone who gets coronavirus recovered fully. Researchers are also still learning about the long-term effects of Covid-19, including inflammation in the brain. Covid-19 has a lot of long-term neurological symptoms including encephalitis (brain swelling), increased risk of stroke, and neurological damage. Its effects can be long-lasting as well. The widespread inflammation through your nervous system can also cause permanent damage, including long-lasting brain fog.

Sudden confusion and intense pain could be a sign of a stroke. Shutterstock.

Sudden Onset Brain Fog Could Indicate a Stroke

While certain lifestyle choices make you more likely to experience a stroke, the onset of a stroke is often sudden. It happens when a blood vessel in the brain bursts or a clot blocks blood flow. Without blood flow and oxygen, brain cells start to die and it affects a person’s ability to communicate. While brain fog is normal, sudden confusion or an inability to speak or understand speech could indicate a stroke. Some other symptoms of a stroke include numbness on one side of the body, trouble seeing, a sudden headache, and trouble walking or loss of balance.

The forgetfulness that comes with baby brain is common in expectant mothers. Shutterstock.

Expectant Mothers and Pregnancy Brain

While research on “baby brain” is mixed, anecdotal evidence tells us expectant and new mothers are more forgetful. Things like hormone fluctuation that happens as a result of fetal development combined with lack of nutrition, stress, and sleep increase the likelihood of brain fog. Pregnancy brain is normal and unfortunately, it doesn’t always subside after birth. Sleepless nights and long days lead to mental cloudiness. While it is normal, you should talk to your doctor if the brain fog becomes overwhelming or if you have concerns about your mental health or postpartum depression.

Hormonal changes from menopause can affect your mental state. Shutterstock.

Menopause Causes Brain Fog

Like hormones playing a role in brain fog during pregnancy, they also play a role in the brain fog that’s common in menopausal women. Brain fog caused by menopause can last for years. It’s caused by falling estrogen levels associated with menopause. Menopausal women also get night sweats that disrupt sleep. Symptoms like feeling too hot and a racing heart wake you up and make it hard to fall back asleep. Not sleeping well makes brain fog more likely, too. For women with severe symptoms, it may be worth seeing a doctor.

Brain fog could accompany symptoms like cramps during your period. Medline Plus.

Even PMS Alters Your Mental State

Like with menopause and pregnancy, hormonal changes from PMS (premenstrual syndrome) alter your mental state. According to research, this is caused by the fluctuating levels of estrogen and progesterone. While brain fog happens with PMS, it’s even more likely to affect people with PMDD (premenstrual dysphoric disorder). This is a severe form of PMS. Additionally, brain fog can happen during a woman’s luteal phase, which happens after ovulation starts but before the actual period. PMS or PMDD should be addressed by your doctor if your symptoms are severe enough they are impacting your life.

Fogginess could be a sign of dangerously low blood sugar. Shutterstock.

Brain Fog Could Indicate a Dangerous Low Blood Sugar Imbalance

Dangerously low blood sugar is a condition known as hypoglycemia. Hypoglycemia happens after fasting, like when you haven’t eaten all day. Some people also experience it in the morning after not eating all night, then waking up. Since your brain primarily uses glucose for energy, when your body drops below normal levels, it results in brain fog. People with diabetes are most likely to experience hypoglycemia, though it can also happen as a result of pregnancy or certain medications. Some people also might experience reactive hypoglycemia. Reactive hypoglycemia happens between 2-4 hours after eating.

Brain fog can be caused by depression and anxiety and is made worse by poor sleep. Shutterstock.

Brain Fog, Depression, and Anxiety

Brain fog is closely linked to mental health conditions like depression and anxiety because they cause stress. Stress affects the area of your brain that regulates things like metabolism, immune response, and the nervous system. The constant stress disrupts your body’s ability to function. Additionally, the stress associated with mental health conditions triggers widespread inflammation that affects the brain. This is made worse by an inability to get a full night of sleep. As not sleeping makes mental health conditions worse, this is a scenario where medical intervention could significantly help symptoms of brain fog.

Inflammation from food sensitivity causes all kinds of inflammatory problems. Shutterstock.

Food Sensitivities and Widespread Inflammation

For people with food sensitivities, inflammation from eating foods your body cannot digest well causes brain fog. Unlike food allergies that cause an immediate, recognizable response, food sensitivities aren’t as severe. However, they do still produce symptoms like joint pain, rashes, upset stomach, and brain fog. While food sensitivities are not life-threatening, symptoms get worse depending on the severity of your condition. For example, people with celiac disease who eat gluten experience inflammation in the small intestine that makes it harder for their bodies to absorb nutrients. Widespread inflammation also makes you more tired.

Autoimmune disorders cause the body to attack itself, resulting in symptoms like brain fog that you can’t always see. Shutterstock.

Autoimmune Conditions and Brain Fog

Autoimmune conditions are notoriously hard to diagnose because symptoms include poor sleep quality, joint pain, fatigue, skin conditions, and body aches. Skin conditions excluded, these symptoms aren’t really visible to the naked eye. This means people can have autoimmune conditions for years before being diagnosed. People who have autoimmune disorders like lupus, fibromyalgia, chronic fatigue syndrome, and multiple sclerosis experience widespread inflammation. This inflammation comes from their cells attacking healthy tissue and it contributes to brain fog. People with autoimmune disorders also struggle with sleep and are physically tired from their symptoms.

Concussions and TBIs present with a variety of neurological symptoms. Shutterstock.

Brain Fog After an Injury Could Be Serious

If brain fog is experienced after an injury, especially one involving the head or neck, you made need a medical evaluation. Less-severe causes of mental cloudiness after an injury are a concussion, which goes away with time. In some cases, it may indicate a traumatic brain injury (TBI). Concussions are a type of TBI, which can be mild, moderate, or severe. In some cases, TBIs cause cognitive, physical, social, and emotional problems. This happens from bleeding, swelling, and other trauma in the brain. Getting treatment for a TBI sooner improves prognosis depending on the severity of the injury.

It is hard to know if memory loss is age-related or caused by neurological conditions like dementia. Shutterstock.

Brain Fog from Age vs. Cognitive Decline

Some cognitive decline is natural as we age. Most people handle it by writing themselves reminders, having routines, and keeping their brains active and challenged. Keeping your brain stimulated generates new brain cells, which slows the death of brain cells that happens with age. Doing things like staying active and eating a brain-healthy diet also supports brain health. In some cases, however, symptoms indicate cognitive decline associated with neural conditions like Alzheimer’s or dementia. If day-to-day tasks become difficult or forgetfulness and short-term memory are severe, talk to your doctor.

Talk to your doctor if your medication makes you foggy- they might adjust the dose. Needpix.

Certain Medications Cause Brain Fog

While there are a lot of medical conditions that cause brain fog, certain medications used to treat them can have similar effects. Brain fog is most likely to occur when taking pain medication, sleep medication, and anti-psychotics, though having your doctor adjust your dosage could help. Some people also become more sensitive to medication with age. People who undergo chemotherapy also experience something known as “chemo brain”, which is characterized by forgetfulness and memory lapses. Chemotherapy causes a cytokine storm like Covid-19 that causes inflammation, though these symptoms might not happen until years after treatment.

An overactive or underactive thyroid affects hormones that cause brain fog. Shutterstock.

Metabolic and Thyroid Issues Cause Mental Cloudiness

Your thyroid glands are responsible for producing important hormones that play a big role in metabolism. People with hyperthyroidism have an overactive thyroid, which is associated with poor concentration, problems with spacial organization, memory lapses, and decreased reaction times. In cases of hypothyroidism, brain fog is especially common because the metabolism is slowed. This also decreases reaction time, increases forgetfulness, and causes low energy levels. In either case, your doctor will monitor thyroid levels and recommend medication or surgery. Treatment for hypo- or hyperthyroidism usually reduces symptoms and improves your quality of life.

Mental burnout has a lot of symptoms that are a sign you should slow down. Shutterstock.

Brain Fog is Normal if You’re Burnt Out

It’s easy to get overwhelmed by all you have to get done in a day and forget to take a break. Whether you’re working on a project for too long or doing something around the house, staying focused on the end goal is a great way to stay motivated. Unfortunately, it also makes it harder for your brain to stay sharp and on task. Burnout is characterized by symptoms like fatigue, headache, and difficulty concentrating. In the long term, it results in sleep problems, weakened immunity, and an increased risk of conditions like heart disease and Type 2 diabetes.

Any viral infection can cause inflammation that slows down your brain. Shutterstock.

Viral Infections Cause Brain Fog

That cloudy feeling you experience when you’re sick isn’t always caused by being tired from your body fighting against infection. Viral infections including upper respiratory infections, Type 1 and 2 herpes, HIV, and other illnesses cause brain swelling that results in brain fog. Illnesses caused by bacteria (like Staph infection), insect bites (like West Nile Virus), or rabies also cause encephalitis. While a little swelling is expected, you should see your doctor if you experience a sudden, severe headache, a high fever, or other neurological symptoms. There could be something seriously wrong.

Cirrhosis makes it harder for your body to eliminate toxins that cause brain fog. Freepik.

Cirrhosis and Your Brain

Your liver plays a critical role in health, as it filters toxins from our body. For people who have cirrhosis, damage to the liver prevents it from working as it should. Conditions like hepatitis C, fatty liver disease, and drinking too much cause cirrhosis. When the liver isn’t functioning well, it causes hepatic encephalopathy. This condition results from the buildup of ammonia and other toxins in the body that the liver isn’t filtering out. For people with cirrhosis, talk to your doctor if brain fog worsens. It could be an indicator your liver is worse.

Processed foods like these make your brain sluggish and slow. Shutterstock.

The Role Your Diet Plays in Brain Health

Sometimes, something as simple as switching up your diet reduces symptoms of brain fog. Caffeine is a popular stimulant, but did you know that starting your day with an apple provides energy, too? The right breakfast prevents that mid-day crash associated with coffee. Your brain needs glucose for energy, which can be found in natural sugars and dietary fiber. When you eat processed or sugary foods, however, all that energy becomes available at once. Brain fog happens when energy stores are depleted. Instead, opt for a fiber-rich breakfast that sustains your brain and avoid heavy foods that will make you feel sluggish.

Sugary foods contribute to poor gut and brain health. Shutterstock.

Too Much Sugar Causes Brain Fog

While I’ve already mentioned diet, the amount of sugar you consume specifically has been linked to problems including brain fog. Processed sugar is also bad for gut health, which plays a big role in hormone production. These hormones control your mood and energy levels. Think about your body like a car. If you try to put poor, low-quality gas in it, then you are going to do damage to the engine. Your brain is the same way. Processed sugar damages gut health, increases your risk of disease, and causes brain fog.

Artificial sweeteners are good for weight loss, but are damaging to your neurological health. Shutterstock.

Artificial Sweeteners Can Also Cause Brain Fog

For people trying to cut calories or reduce sugar intake, artificial sweeteners have been advertised as a way to let them do that without making sacrifices. While sweeteners are a good way to reduce sugar and calorie intake, research shows that there could be disastrous consequences for your brain. In a ten-year study, it was found consuming artificial sweeteners triggers neurological symptoms and inflammation in the brain. The study found people were three times as likely to suffer a stroke or end up with dementia after consuming artificially sweetened products.

Certain vitamin deficiencies make brain fog more likely. Shutterstock.

Consider Vitamin D or B12 Deficiencies

Vitamin deficiencies could also be contributing to your foggy feeling. Vitamin B12 is critical for the health of your red blood cells and central nervous system. When you’re deficient, you may experience symptoms of confusion, memory problems, loss of balance, and depression. Low levels of Vitamin D have also been linked to brain fog because of its role in mental health. Additionally, Vitamin D has been linked to better cognitive function, particularly in aging adults. Adding nutrient-rich foods to your diet is a good idea, but a multivitamin or supplement helps with any holes in your diet.

Close up vitamins and supplements on white background with a brown bottle. Including Vitamin c, vitamin E, vitamin D3, salmon oil, fish oil and co enzyme Q10 capsules.
Certain supplements like fish oil decrease inflammation and strengthen neural pathways to improve brain health. Shutterstock.

Consider Supplements for Brain Fog

Cognitive decline happens naturally, based on a combination of our genetics, lifestyle factors, and how gracefully our brains age. Adding certain supplements can slow this natural decline and support brain health, which reduces the risk of brain fog. Fish oil is well-known for its role in improving brain health. Adding B vitamins and antioxidants like vitamins A, C, and E or natural supplements like gingko bilboa and ginseng extract also support your brain. While dietary supplements are generally considered safe, you should talk to your doctor if you have a pre-existing medical condition or are currently taking medication.

Heavy metals from your environments get trapped in brain tissue and cause neurological symptoms. Shutterstock.

Beware of Exposure to Heavy Metals

People are exposed to trace amounts of heavy metals all day. There are trace amounts in household products, building materials, beauty products, and even foods. While our bodies are good at filtering out metals and other toxins, too much exposure can become dangerous. Research has even linked over-exposure to lead, cadmium, and manganese to Alzheimer’s disease. Having your blood tested for levels of metals could help you narrow down what you are being exposed to. You can also take steps like sleeping well, staying hydrated, and eating a diet that supports detoxification.

If your head feels cloudy after a workout, you might be dehydrated. Shutterstock.

Hydration is Critical to Brain Function

Did you know that you only need to be 1% dehydrated to experience a 5% decrease in cognitive function? This happens because our bodies are primarily made of water. Even this slight decrease makes people perform worse on cognitive tasks and results in symptoms like headache, fatigue, and problems concentrating. Severe hydration causes muscle cramps, electrolyte imbalances, dizziness, and even loss of consciousness. According to Harvard University, people need an average of 4-6 cups of water per day because they are also getting water from food. However, this changes based on factors like your weight and how active you are.

A sedentary lifestyle is dangerous to your overall health. Shutterstock.

A Sedentary Lifestyle Can Make You Foggy

Research shows a sedentary lifestyle has a lot of consequences and generally increases your risk of mortality, heart disease, and cancers. Whether you are physically active affects much more than just your weight. Physical activity helps burn off cortisol that accumulates in your body over time. Additionally, it encourages blood flow that sends nutrients to the brain. This helps with the formation of new brain cells that eliminate some of that foggy feeling. In addition to brain benefits, physical activity is also important for keeping your physical body healthy, including your joints and cardiovascular system.

People with chronic dry eyes and brain fog could be struggling with Sjorgen’s syndrome. Shutterstock.

Brain Fog with Dry Eyes Could Be Sjogren’s Syndrome

Sjogren’s syndrome is an autoimmune disease that doesn’t have a lot of noticeable symptoms. However, if you are experiencing mental cloudiness paired with dry eyes, it could be because your body is attacking healthy tissue and causing swelling in your tear ducts and saliva glands. This makes it hard for your body to produce tears and saliva. It can even make it hard for some people to have sex without another form of lubrication. While researchers aren’t sure what causes Sjogren’s syndrome, it’s worth talking to your doctor about testing if you have these symptoms.

A severe migraine could be an inconvenience, or a sign of something serious like a blood clot or stroke. Shutterstock.

Brain Fog with a Migraine Could Be Serious

People often brush off their migraine as a bad headache or something to do with their sinuses. However, migraines can be serious. They affect 1 in 6 people, with women in their 30s and 40s and people with a family history most likely to be affected. Migraines cause brain fog because they are triggered by an inflammatory response in the brain that causes pain and other neurological symptoms. Migraines can be serious or even early signs of a stroke, so if you experience confusion, difficulty speaking, numbness, or other severe symptoms, it’s worth being evaluated.

Some insects and spiders cause serious neurological symptoms. Shutterstock.

Bites or Rashes with Brain Fog Could Be Serious

Some insects and arachnids carry disease with their bites. One of the more common bites that cause brain fog is a tick bite. Ticks sometimes carry Lyme disease. Spider bites from a Black Widow or another toxic critter can also cause neurological symptoms. Earlier mental symptoms include confusion, trouble holding a conversation, and problems finding the right word. However, you are more likely to notice the pain during or after a bite than the mental symptoms. Ticks leave behind a “bulls-eye” pattern, while a Black Widow bite becomes red and swollen over time.

The people around you might notice symptoms before you- listen. Shutterstock.

See a Doctor if Other People Notice Your Brain Fog

One of the problems with brain fog is that it isn’t always easily noticed in milder cases. It’s also easy to brush forgetfulness off as something that just “happens” when we’re a little sleepy. However, if brain fog is impacting your life or its effects are severe enough that other people notice, it might be time to see a doctor. Often, the people we are closest to might notice symptoms before we do. It’s not always easy to hear that your brain isn’t doing what it should, but recognizing the problem earlier means finding a solution sooner.

Take note of any symptoms occurring with brain fog so you can bring them up to your doctor. Shutterstock.

Brain Fog and Other Symptoms

Being aware of other symptoms that present with brain fog also helps with determining the cause of brain fog and the best course of treatment. The way brain fog is treated changes based on the cause. In some cases medication is beneficial. For others, it’s best to manage symptoms by making dietary changes or reducing stress. There are also apps to create reminders to help manage your symptoms. Since brain fog comes and goes, track when you feel foggy and other symptoms. Your doctor will use this information and other diagnostic tests to help you find a solution.

Being aware of your family history of disease helps you watch for certain symptoms. Shutterstock.

Talk to Your Doctor if You Have a Family History of Neurological Problems

While people develop neurological conditions for many different reasons, family genetics plays a big role in what conditions you are more likely to end up with. This is especially true with conditions like multiple sclerosis or Alzheimer’s disease. They aren’t necessarily passed down through families, but they have certain genetic markers that are passed down. There is no guarantee that you’ll end up with a condition because you are genetically predisposed. However, it does mean that if you have neurological symptoms like persistent brain fog, it is worth discussing with your doctor.

Medicine is always advancing, so ask your doctor about new ways to manage symptoms at your annual checkup. Shutterstock.

Chronic Conditions and Annual Checkups

For people with chronic conditions, it’s easy to push off brain fog as “just another symptom” that you have to learn to deal with. However, brain fog that doesn’t seem to go away or that has gotten worse could be a sign that you need to take different steps to manage your condition. The best thing to do is to keep a journal of symptoms and document when you are experiencing brain fog. Your doctor may be able to use this information at your annual checkup to help you come up with a plan for treating it.


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