Brain fog can be a symptom of several medical conditions. It affects a variety of mental processes, including memory and concentration.

Brain fog can occur with migraine, multiple sclerosis, during pregnancy, and due to things such as stress, lack of sleep, or diet.

Brain fog can be frustrating and confusing. However, people can use several methods to help themselves cope.

This article reviews what brain fog is, what causes it, and tips on managing it.

Brain fog can be described as a feeling of confusion and disorientation.

It is not considered a medical condition by itself, and as such, it has no diagnostic criteria. Instead, it describes symptoms associated with cognitive impairment that can have many causes.

Brain fog can make a person feel as though the processes of thinking, understanding, and remembering are not working as they should.

Brain fog can affect:

  • memory, including the ability to store and recall information
  • the use and understanding of language
  • the ability to process and understand information
  • visual and spatial skills for drawing, recognizing shapes, and navigating spaces
  • the ability to calculate and work things out
  • executive functioning abilities for organizing, solving problems, and planning

If one or more of these functions does not work effectively, it can be difficult to understand, focus, and remember things. It can lead to stress and mental fatigue.

Brain fog can present differently between people. Some common symptoms can include the following:

  • lack of mental clarity
  • memory issues
  • inability to focus

Many conditions that can cause brain fog are inflammatory conditions.

There are different types of inflammation. Chronic inflammation is caused by an out-of-balance immune system and can affect any part of the body in different ways.

This inflammation can affect the heart and its vessels, the gut and its biome, the liver, as well as the brain’s neurons and cognition. Low-grade inflammation can also occur in a specific organ or tissue, including brain tissue.

A person can also experience acute inflammation, which can result from a traumatic head injury, for example.

Below are examples of conditions that may cause brain fog, usually due to a type of inflammation.

Concussion

A concussion can happen after trauma or a head injury such as a fall. It can cause acute inflammation in the brain, leading to cognitive brain fog-like symptoms such as memory problems, confusion, or forgetfulness.

Other signs include headache and mood changes. A person may also lose consciousness.

Migraine

Migraine is a condition that can cause recurring headaches, which can sometimes be debilitating. Migraine episodes can also involve other symptoms, such as sensitivity to light and sound, mood changes, and brain fog.

While more research is needed to understand why this happens, many people report experiencing difficulties with cognition before or during a migraine attack.

One theory is that migraine causes cortical depression, which is a change in brain activity that can lead to brain fog. Migraine is also associated with the inflammation of vessels and tissues in the brain.

Multiple sclerosis

Inflammation can cause brain fog. In cases of MS, the inflammation causes gradual damage to the myelin in the brain.

As a result, people living with MS may experience changes in their ability to make decisions and process and remember information.

These changes are usually mild to moderate and do not affect a person’s ability to live independently. However, they can lead to frustration and difficulty completing daily tasks, such as finding house keys or shopping for groceries.

Learn more about how MS affects the brain.

Fibromyalgia and chronic fatigue syndrome

Fibromyalgia and chronic fatigue syndrome are also inflammatory conditions.

Fibromyalgia causes pain throughout the body and can affect a person’s concentration and memory. This is known as fibro fog. Scientists do not know exactly how fibromyalgia leads to these types of symptoms.

CFS, also known as myalgic encephalomyelitis, can result in severe tiredness and problems with thinking. As with fibromyalgia, there is no clear explanation of what CFS does to the brain to cause brain fog symptoms.

Infections

Brain fog can be a symptom of an inflammatory infection that attacks the brain. For example, bacterial diseases such as Lyme disease can cause brain fog.

A person can also experience brain fog from a fungal infection after inhaling a substance such as mold. Viral infections can also lead to brain fog. Examples of such viruses include West Nile virus and COVID-19.

Many people experience problems with their cognition after having COVID-19, even long after the initial infection has passed. This can be one of the symptoms of long COVID.

The virus is thought to activate certain immune cells in the brain, which cause inflammation, making it difficult for the brain to perform day-to-day cognitive tasks.

Learn more about long COVID brain fog.

Mood disorders

Mood disorders such as depression, anxiety, or bipolar disorder can impact how someone thinks and feels.

Research shows that depression can negatively affect a person’s ability to remember and think clearly. This may be related to inflammation in the nervous system that affects the brain.

Researchers have made similar conclusions about anxiety. In addition, researchers have found that both depression and bipolar disorders can lead to certain abnormalities in the brain.

Problems with memory, focus, and decision-making can contribute to the feeling of brain fog. There may also be problems with sleeping and a lack of energy, which can make concentrating and completing tasks harder.

Learn more about brain fog and depression.

Neurodiversity

Neurodivergent people, including autistic people, can experience brain fog. The cause may be the development of inflammatory molecules in the brain.

In many cases, autism spectrum disorder (ASD) can co-occur with anxiety, which can worsen brain fog.

In addition, brain fog and other cognitive symptoms can occur with attention deficit hyperactivity disorder (ADHD), particularly in adults.

Nutrient deficiency

Nutrients can have an effect on a person’s ability to focus, think clearly, and recall information.

Eating an unhealthful diet or not eating enough can cause problems with healthy brain function. Deficiencies can also often occur due to underlying inflammatory health conditions such as Celiac disease.

Specific nutrients that can play a role in cognition and memory include vitamin B-12, iron, and Omega-3 fatty acids. A lack of some nutrients, such as magnesium, can also contribute to the development of mood disorders that can also lead to brain fog.

Learn more about how certain nutrients can cause brain fog.

Alzheimer’s disease

Alzheimer’s and other types of dementia can involve symptoms of brain fog.

Alzheimer’s happens when protein plaques build up in a person’s brain. This buildup affects brain functioning, with various cognitive and other symptoms. There is research indicating brain inflammation plays a role in this process.

Learn more about Alzheimer’s disease.

Obesity

People with obesity may also experience brain fog. This is likely because obesity can cause inflammation affecting multiple body systems, including the brain.

In a 2020 review, researchers noted that evidence supports the idea that obesity leads to cognitive impairment and potential changes in brain structure.

Autoimmune conditions

Autoimmune conditions are inflammatory diseases. Brain fog can be a symptom of an autoimmune condition.

For example, lupus is an autoimmune disease that occurs when the immune system attacks healthy tissue. It can cause symptoms throughout the body.

About 70–80% of people with lupus experience brain fog at some point in their lifetime.

Another condition that can cause brain fog is rheumatoid arthritis. Similarly, inflammatory bowel disease (IBD) is another condition in which gastrointestinal inflammation can also affect brain function.

There are additional conditions that may cause brain fog. They include:

Hormonal changes

Changes to a person’s hormone levels can affect their brain functioning, especially during pregnancy or menopause. People going through menopause often cite brain fog as an issue affecting them.

Hypothyroidism and Hashimoto’s thyroiditis can lead to hormone imbalances. Memory and thinking problems that are similar to brain fog are common in thyroid disorders.

Learn more about hypothyroidism.

Postural tachycardia syndrome

Some people experience unusual changes in heart rate and blood pressure when standing up. This is a condition doctors call postural tachycardia syndrome (POTS).

A 2020 study noted that alertness and impaired short-term memory may underlie reports of brain fog in people with POTS.

Sleep apnea

During sleep, the muscles in the back of the throat relax. Sometimes, this can lead to people having trouble breathing at night.

If a person has pauses in breathing at night that interfere with their sleep quality, they may have sleep apnea.

Treating sleep apnea may improve the brain fog that can result.

Medication

Some medications may affect an individual’s mental functioning.

These include:

  • chemotherapy drugs
  • sleeping pills
  • drugs for anxiety
  • some pain relief medications
  • statins
  • corticosteroids

People may wish to speak with a doctor about any adverse side effects they are experiencing from the medication they are taking. If the medication cannot be changed, a doctor can help the individual develop coping strategies for brain fog.

A person should consider talking with a doctor about treating the underlying cause of their brain fog. It should clear or improve when the underlying condition is treated or managed, such as by switching medications.

The following are some ways a person can treat the symptom of brain fog. However, they will not generally treat the underlying condition.

Diet

Dietary changes may increase a person’s energy levels and improve mental focus.

A diet that focuses heavily on processed foods that are high in unhealthful fats and sugars may contribute to brain fog. Replacing these foods with fresh fruits, vegetables, and other fresh, plant-based foods can help promote clearer thinking.

Foods that contain the various A, B, C, and D vitamins and omega-3 oils may also benefit brain function.

In addition, people living with many of the conditions that can cause brain fog may benefit from probiotic supplements. Research shows this can help improve brain function. A person may find a similar benefit from eating foods that naturally contain probiotics, such as yogurt or kimchi.

People should also drink enough fluid to prevent dehydration but limit the intake of caffeine and alcohol, as these can affect sleep and energy levels.

Exercise

A 2018 review concluded that physical exercise can physically and psychologically benefit the brain. The authors recommend it for improving both thinking ability and mood.

Current guidelines advise adults to engage in either 150 minutes a week of moderate-intensity aerobic exercise or 75 minutes a week of high intensity activity, as well as exercises to improve strength and flexibility.

Sleep hygiene

Sleep hygiene refers to how a person sets up their sleep environment and improves their sleep quality. Research shows that sleeping well can help reduce body inflammation.

Some tips to help improve sleep quality include:

  • set a regular bedtime
  • leave mobile devices in another room
  • keep the room cool, dark, and free from sound, or other distractions
  • use the bed only for sleeping and sex
  • avoid caffeine before bed
  • do not eat a large meal before bedtime

Learn more tips for better sleep.

Stress management

When a person is exposed to something that triggers a stress response, the immune system becomes inflamed, which can contribute to brain fog symptoms. Therefore, controlling stress can help a person maintain a clearer mind.

Stress management can vary between people. For some, exercises such as yoga or running can help improve their mood and stress levels.

Others may benefit from mindfulness meditation, deep breathing techniques, or similar methods to help reduce their stress.

Most people will benefit from avoiding stressful situations, such as public speaking or a demanding job.

Learn about ways to reduce stress.

Supplements to help stop brain fog

Some evidence suggests that vitamin and mineral deficiencies may contribute to brain fog, particularly when an underlying condition is present, such as Celiac disease. Supplements may help to eliminate brain fog associated with vitamin deficiencies.

Supplements that may help with brain fog include:

  • Vitamin D: Vitamin D deficiency may contribute to brain fog. Vitamin D supplements may help. In a 2019 study, researchers found that supplementing with vitamin D helped improve mental cognition in older women who took 3 doses of vitamin D daily for a year.
  • Omega-3 fatty acid: Some older evidence suggests that taking omega-3 fatty acid supplements may help improve mental cognition.
  • Vitamin C: A 2019 study found that healthy adults with high levels of vitamin C in their blood performed better on cognitive tasks, such as focus, attention, memory access, and reaction time.
  • L-theanine: A 2021 study found that taking a 100.6 milligram (ml) dose of L-theanine helped to improve working memory and reaction times on cognitive tests.
  • B complex: A 2020 study of over 200 adults with cognitive impairment and B12 deficiencies found that most people performed better with cognition and attention when taking supplements.
  • Magnesium: Some evidence suggests that low magnesium levels can increase the risk of cognitive impairment

There are many possible causes of brain fog, and treatment will depend on the cause.

A doctor may work with a person to develop a care plan that includes medication, physical therapy, and self-care through diet and exercise.

Sometimes, a doctor may prescribe specific medications to help with aspects of thinking, such as:

  • depression
  • fatigue
  • mood changes

Donepezil (Aricept), a treatment for people with Alzheimer’s disease, may also help those with brain fog from MS.

The following lifestyle tips may help with improving symptoms of brain fog:

  • prepare meals ahead of time to avoid eating fast food or other processed foods when running errands, at work, or at other times during travel
  • develop a routine that includes a regular time for exercise
  • try to go to sleep around the same time every night
  • engage in regular physical activity
  • avoid or limit alcohol and other substances
  • eat foods that contain probiotics

Tips for managing daily tasks

Several strategies may help when it becomes difficult to think clearly.

  • Use a calendar: Write down your daily, weekly, and monthly tasks in a calendar or organizer.
  • Avoid distractions: When possible, find a quiet space to concentrate on tasks and take regular breaks to help focus.
  • Do one task at a time: Focus on one task and complete it before beginning another one. Multitasking can worsen confusion and brain fog, and it can also increase stress.
  • Get support: Explain how you feel to family and friends and ask them to speak more slowly. This will allow extra time to process information.
  • Learn organization techniques: It may help to keep a diary or make lists. Smartphone reminders may help remind you to complete tasks, such as taking your medication or going to doctor’s appointments.
  • Store items in the same place each time: Find somewhere memorable in the home to keep items that are easy to lose, such as keys.

Strategies to help with memory and concentration can make the situation more manageable in cases where brain fog is part of a long-term condition.

A person should see a doctor if they:

  • have other symptoms that may indicate an underlying medical condition
  • notice that brain fog has started or worsened suddenly or significantly
  • see no improvement despite making lifestyle changes

A doctor will usually ask for information about their mental health, diet, and other symptoms before carrying out tests.

The following sections provide answers to some frequently asked questions about brain fog.

Does brain fog go away?

Brain fog can last for months. However, it often improves when a person gets effective treatment the underlying cause. A person can also take steps to help improve the symptom with lifestyle changes and other treatments.

Is brain fog a mental illness?

Brain fog is not a mental health condition. However, mental health conditions such as depression can cause brain fog to occur.

Does coffee help with brain fog?

Coffee may provide a temporary boost and may also help with the long-term prevention of cognitive decline. According to a 2016 study, daily consumption of caffeine or coffee can help lower a person’s risk of developing Parkinson’s disease, Alzheimer’s disease, or a stroke.

Brain fog can happen for various reasons, including a medical condition, stress, poor diet, a lack of sleep, or the use of some medications. If symptoms result from a medical condition, they may improve with treatment.

Tips for reducing the impact of problems with memory and concentration include making lists, sticking to routines, reducing stress, improving sleep, and regular exercise, among others.

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