What Causes Brain Fog? A Holistic Approach to Understanding Mental Clarity
Have you ever walked into a room and forgotten why you were there? Struggled to find the right word during a conversation? Read the same paragraph several times without absorbing it? Felt mentally slow, unfocused, or unusually forgetful?
You may be experiencing what many people call brain fog.
Brain fog is not a specific medical diagnosis. Rather, it is a common term for problems with concentration, memory, mental clarity, word-finding, attention, and processing information. Research suggests that brain fog can have many contributing factors, which is why looking at the whole person can be useful when trying to understand persistent symptoms.
From a holistic perspective, the goal is not simply to ask, "How can we make the brain work better?" It is also important to ask, "What factors throughout the body may be interfering with healthy cognitive function?"
1. Poor Sleep
Sleep is one of the most important foundations for mental performance. Inadequate sleep, fragmented sleep, insomnia, or an inconsistent sleep schedule can affect attention, memory and mental processing.
Interestingly, research examining brain fog in several populations identifies sleep and fatigue among commonly reported contributors.
If you are sleeping seven or eight hours but still waking up exhausted and mentally foggy, it may be worthwhile to look beyond the number of hours slept and consider sleep quality.
2. Nutritional Imbalances
The brain requires a steady supply of nutrients and energy to function properly.
Inadequate intake or deficiencies involving nutrients such as iron, vitamin B12, folate, vitamin D and other essential nutrients may contribute to fatigue or cognitive symptoms in some people.
Nutrition is therefore an important part of a comprehensive approach to brain health. Rather than automatically assuming that supplements are the answer, a more thoughtful approach is to evaluate dietary patterns and, when appropriate, consider laboratory testing for nutritional status.
3. Thyroid Problems
Thyroid function can affect many aspects of health, including energy, mood and cognitive function.
People with hypothyroidism sometimes report "brain fog," including problems with memory, concentration and mental clarity. A review published in Thyroid examined the phenomenon specifically and concluded that cognitive symptoms can be an important concern for people with hypothyroidism.
For someone experiencing persistent brain fog—particularly when accompanied by fatigue, feeling cold, changes in weight, constipation, dry skin or other symptoms—thyroid function may deserve consideration.
4. Chronic Stress
The brain does not operate independently from the rest of the body.
Long-term psychological or physical stress can affect sleep, energy, mood and the ability to concentrate. People experiencing chronic stress may feel as though their minds are constantly "running," making it difficult to focus on one task at a time.
A holistic approach considers the interaction among stress, sleep, nutrition, physical activity and overall health rather than treating each symptom as an isolated problem.
5. Hormonal Changes
Hormonal changes can also coincide with cognitive symptoms.
Brain fog is commonly reported during the menopausal transition, along with changes in sleep and mood. A recent review found that cognitive complaints and brain fog are common during this period and can affect quality of life and productivity.
Hormonal health may therefore be an important consideration when brain fog develops during periods of significant hormonal transition.
6. Inflammation and Immune-System Changes
Another area of growing research is the relationship between inflammation, immune-system activity and cognitive function.
This has received particular attention in people with long COVID. A recent systematic review of more than 25,000 people found brain fog and cognitive impairment to be common among individuals with long COVID. Researchers have proposed several possible mechanisms, including neuroinflammation, immune dysregulation and microvascular changes, although the underlying causes remain incompletely understood.
This does not mean that ordinary brain fog is necessarily caused by inflammation. Rather, it demonstrates why persistent cognitive symptoms may warrant a broader health evaluation.
7. Medications, Illness and Other Health Conditions
Brain fog can sometimes occur in association with medications, chronic illnesses, mood disorders, anemia, sleep disorders and other conditions.
Because brain fog has many possible causes, persistent or worsening cognitive symptoms should not simply be attributed to aging or stress. A healthcare professional can help determine whether further evaluation is appropriate.
A Holistic Approach to Brain Fog
At Haas Wellness Centers, we believe that persistent symptoms deserve careful attention rather than simply being ignored.
A holistic evaluation may consider several areas that can influence how a person feels and functions, including:
Nutrition and dietary patterns
Sleep and stress
Thyroid health
Digestive health
Nutritional status
Immune-system balance
Environmental exposures
Physical and structural factors
Lifestyle habits
Appropriate laboratory testing
Depending on an individual's history and symptoms, additional laboratory evaluation may help identify nutritional, metabolic, thyroid or other factors that deserve further attention.
The objective is to develop a more complete picture of the individual rather than focusing on brain fog as an isolated symptom.
How Haas Wellness Centers Can Help
If you are experiencing persistent brain fog, fatigue, poor concentration or difficulty with memory, Haas Wellness Centers in Charlotte, NC, can help you take a more comprehensive look at the factors that may be contributing to your symptoms.
Our approach emphasizes individualized evaluation, education and personalized wellness strategies. When appropriate, laboratory testing and other assessments can provide additional information that may help guide the next steps.
Brain fog may be your body's way of telling you that something needs attention.
Don't simply accept feeling mentally exhausted, unfocused or forgetful as a normal part of getting older.
Contact Haas Wellness Centers in Charlotte, NC to learn more about a personalized approach to understanding brain fog, fatigue and overall health.
References
Kverno K. Brain Fog: A Bit of Clarity Regarding Etiology, Prognosis, and Treatment. Journal of Psychosocial Nursing and Mental Health Services. 2021.
Samuels MH, Bernstein LJ. Brain Fog in Hypothyroidism: What Is It, How Is It Measured, and What Can Be Done About It. Thyroid. 2022;32(7):752–763.
Williams M, Maki PM, et al. A Review of Cognitive, Sleep, and Mood Changes in the Menopausal Transition. Obstetrics & Gynecology. 2025.
van der Feltz-Cornelis CM. Cognition and Long COVID: a Review. Current Neurology and Neuroscience Reports. 2026.
Chakraborty C, et al. Long COVID-associated neurological symptoms and brain fog: Understanding the mechanism of neuroinflammation, BBB disruption, diagnostics, and therapeutics. Molecular Biology Reports. 2026.
Ceban F, et al. Fatigue and cognitive impairment in Post-COVID-19 Syndrome: A systematic review and meta-analysis. Brain, Behavior, and Immunity. 2022.
