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

It can occur with multiple sclerosis, during pregnancy, and as a result of lifestyle factors, such as stress, lack of sleep, or an unhealthful diet.

Brain fog can be frustrating and confusing, but there are ways to cope when it happens.

Learn more in this article about what brain fog is and what causes brain fog, and get some tips on how to manage it.

Brain fog may cause confusion and disorientation, affecting memory, information processing, and spatial awareness.Share on Pinterest
Brain fog involves feelings of confusion and disorientation.

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

It can affect their:

  • memory, including the ability to store and recall information
  • use and understanding of language
  • ability to process and understand information
  • visual and spatial skills for drawing, recognizing shapes, and navigating spaces
  • 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.

Various conditions can lead to brain fog.

Multiple sclerosis

People who live with MS may experience some changes in their ability to make decisions and to 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 here about MS.

Fibromyalgia and chronic fatigue syndrome

Fibromyalgia causes pain throughout the body and can affect a person's concentration and memory.

Chronic fatigue syndrome (CFS) is another chronic, or long-term, condition. It can result in severe tiredness and problems with thinking.

Depression and stress

Depressed woman, sitting against wall and holding head in hand.Share on Pinterest
Depression can lead to a loss of concentration.

Depression is a serious mood disorder that affects how someone thinks and feels. 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.

Stress and anxiety can also make it difficult to think clearly.

Iron deficiency anemia

If red blood cells cannot deliver enough oxygen to the body's organs and tissues, a person may experience mental and physical tiredness and other symptoms, such as shortness of breath and brain fog.

Hormonal changes

Changes to a person's hormone levels can affect their brain functioning, especially during pregnancy or menopause.

One small study from 2013 found that hormonal changes during the menopausal transition made it harder for women to take in and remember new information and to focus their attention on challenging tasks.

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

What is hypothyroidism? Learn more here.

Postural tachycardia syndrome

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

A study appearing in 2013 reported that adolescents with POTS said they often had symptoms of brain fog, such as confusion, forgetfulness, "cloudy" thinking, and difficulty focusing, thinking, and communicating.

Find out more here about POTS.

Alzheimer's disease

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

Alzheimer's happens when plaques of protein build up in a person's brain. This buildup affects brain functioning, with various cognitive and other symptoms.

Learn more here about Alzheimer's disease.

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.


People with obesity may also experience brain fog. Scientists believe there may be a link between brain fog, obesity, and inflammation, which is a feature of obesity.


Some medications can 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 to 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.

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If making lifestyle choices does not help, a doctor may recommend medication.

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.

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

A doctor may work with the individual 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, a treatment for people with Alzheimer's disease, may also help those who have brain fog with MS.

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, and explaining to friends and family how they can help.