Brain fog is characterized by memory impairment, difficulty concentrating, and a change in cognitive abilities. People might describe it as a mentally fuzzy feeling that makes it hard to focus and concentrate. Brain fog is not a medical diagnosis. Instead, it is a constellation of symptoms that may be due to a medical condition or a combination of lifestyle factors. While any change in cognitive health is concerning, brain fog symptoms can usually be improved or treated after identifying the underlying cause.
Health conditions and factors that may cause brain fog include:
Brain fog symptoms may feel different for each person. Here are some common brain fog symptoms:
Confusion is the state of being unable to think clearly or feeling like your mind is not clear. As a result, you may find it hard to make decisions or focus on conversations. Tasks that previously felt effortless may now cause fatigue. Confusion is more common in older adults and can be difficult to distinguish from dementia and delirium.
A sudden onset of confusion may indicate a serious medical condition. Healthcare providers frequently use the mnemonic AEIOU-TIPS to consider the common medical causes of confusion.
If you have physical signs or symptoms, concerns about a medical condition causing confusion, or your confusion is noted by another person, get medical help immediately. Many causes of confusion are reversible with treatment.1
Each person may describe an inability to concentrate differently, but it usually involves losing focus, having trouble starting or completing tasks, making mistakes, and having trouble thinking clearly.
Inability to concentrate can have many causes, including:
If you cannot concentrate and are having trouble focusing, try the following:
If the inability to concentrate persists or worsens, or if you have decreased performance at work or school, see your doctor to see if a medication or medical condition may be causing it.
Brain fog is often caused by physical and mental fatigue, not getting enough sleep, being dehydrated, or feeling faint.3 Chronic fatigue syndrome is persistent fatigue lasting more than six months that causes physical and cognitive symptoms. The cognitive symptoms are commonly described as brain fog.4
Tiredness and brain fog can be caused by low blood pressure, not drinking enough water, medical conditions, medications, anxiety, depression, and infections.
To reduce fatigue and brain fog, try some of these:
See your healthcare provider if you have symptoms associated with fatigue or if fatigue persists or worsens.
Disorganization can be a cause or an effect of brain fog. Fatigue and an inability to concentrate can lead to disorganization. Likewise, disorganization can contribute to forgetfulness and confusion.
Strategies to reduce the stress of disorganization include the following:
Some forgetfulness is normal, especially if you are excessively stressed, busy, or trying to multitask. But when forgetfulness makes it difficult to get through your day, it is a problem. Forgetfulness can take its toll on your relationships, job security, and self-esteem.
Memory lapses can be concerning and trigger fears of dementia or Alzheimer’s disease. But stress, not getting enough sleep, medications, heavy alcohol use, and aging can all cause forgetfulness.
According to the National Institute on Aging, examples of normal forgetfulness may include making an occasional bad decision, missing an occasional payment or bill, forgetting an appointment but recalling it later, having occasional problems with word choice, and losing things from time to time. When these are persistent or recurrent problems, it is important to have a medical evaluation.5
Sluggishness is a lack of energy or alertness. It can be physical, mental, or both. Like fatigue, sluggishness can be caused by a medical condition, a mental health condition, medication side effects, or lifestyle factors.
Sluggishness may be caused by the following:
If sluggishness is persistent, worsening, or associated with symptoms, talk to your healthcare provider to see if it has an underlying physical cause.
Some people with brain fog symptoms also experience difficulty communicating. Speech difficulties can be due to muscle weakness or fatigue. Word finding and the inability to complete a sentence can be due to difficulty concentrating or delayed processing speed.6
If you have speech difficulties, a speech-language pathologist can help you determine whether they are due to a physical or cognitive impairment and develop a treatment plan to help resolve them.
Brain health and mental health intersect, which can sometimes make diagnosis challenging. Mental health conditions, dementia, and other brain diseases affect aspects of brain function besides memory and concentration. They are frequently accompanied by neurologic signs that the brain is not functioning correctly.
Knowing the symptoms of brain fog can help you determine whether your symptoms are likely due to brain fog or a more serious condition. See your doctor for a full evaluation if your symptoms persist, worsen, or involve aspects of cognitive function other than memory and concentration. Discuss your brain fog symptoms with your healthcare provider. They may suggest a treatment plan that reduces these symptoms.
While we strive to always provide accurate, current, and safe advice in all of our articles and guides, it’s important to stress that they are no substitute for medical advice from a doctor or healthcare provider. You should always consult a practicing professional who can diagnose your specific case. The content we’ve included in this guide is merely meant to be informational and does not constitute medical advice.
1. Espino DV, Jules-Bradley AC, Johnston CL, Mouton CP. Diagnostic approach to the confused elderly patient. Am Fam Physician. Mar 15 1998;57(6):1358-66.
2. Tucker KL. Nutrient intake, nutritional status, and cognitive function with aging. Ann N Y Acad Sci. Mar 2016;1367(1):38-49. doi:10.1111/nyas.13062
3. Ross AJ, Medow MS, Rowe PC, Stewart JM. What is brain fog? An evaluation of the symptom in postural tachycardia syndrome. Clinical Autonomic Research. 2013;23(6):305-311. doi:10.1007/s10286-013-0212-z
4. Ocon AJ. Caught in the thickness of brain fog: exploring the cognitive symptoms of Chronic Fatigue Syndrome. Front Physiol. 2013;4:63. doi:10.3389/fphys.2013.00063
5. National Institute on Aging. Do Memory Problems Always Mean Alzheimer’s Disease? Accessed November 16, 2022. https://www.nia.nih.gov/health/do-memory-problems-always-mean-alzheimers-disease#:
6. Ramage AE. Potential for Cognitive Communication Impairment in COVID-19 Survivors: A Call to Action for Speech-Language Pathologists. Am J Speech Lang Pathol. Nov 12 2020;29(4):1821-1832. doi:10.1044/2020_ajslp-20-00147