What’s the Difference Between Brain Fog and Dementia?

Last Updated: December 2025

TL;DR

Brain fog is a reversible state of slowed thinking, poor focus, or mental cloudiness—often caused by stress, inflammation, sleep issues, hormonal shifts, blood sugar swings, or post-viral changes. Dementia is a progressive decline in memory and cognitive function that interferes with daily life. At Insight Functional Health in Silver Spring, MD, Dr. Anna Sattah, MD, IFMCP, evaluates both using a systems-based, root-cause approach inspired by critical-care precision and advanced brain-health frameworks such as Dr. Dale Bredesen’s ReCODE 2.0 protocol.

Key Points

• Brain fog = functional impairment (attention, clarity, recall), often temporary and reversible.
  
• Dementia = structural + progressive decline, affecting memory, reasoning, language, and daily function.
  
• Brain fog can be triggered by inflammation, hormonal imbalance, gut dysfunction, stress dysregulation, long COVID, poor sleep, or metabolic issues.
  
• Dementia involves neurodegeneration, vascular changes, or conditions like Alzheimer’s disease.
  
• Functional medicine identifies root causes affecting cognition, including insulin resistance, toxins, infections, oxidative stress, and mitochondrial dysfunction.
  
• Dr. Sattah uses evidence-based testing, personalized interventions, and Bredesen-informed protocols to support cognitive clarity and long-term brain health.
  

What This Means in Plain English

Many patients worry that their brain fog might be early dementia—but they are not the same.

Brain fog feels like:

• Sluggish thinking
  
• Trouble focusing
  
• Forgetting words
  
• "Not feeling sharp"
  
• Difficulty multitasking
  

It often fluctuates and improves with proper treatment.

Dementia affects:

• Memory (especially recent events)
  
• Problem-solving
  
• Recognizing familiar places or people
  
• Performing routine tasks
  
• Decision-making
  

Dementia interferes with daily life and usually worsens unless the underlying causes are identified and treated early.

What Causes Brain Fog?

Brain fog often arises from reversible sources such as:

• Hormonal shifts (perimenopause, thyroid)
  
• Post-viral inflammation (including long COVID)
  
• Poor sleep, apnea, or circadian disruption
  
• Gut dysbiosis or chronic inflammation
  
• Blood sugar swings or insulin resistance
  
• Nutrient deficiencies (B12, iron, omega-3s, vitamin D)
  
• Chronic stress and cortisol imbalance
  
• Mold or environmental toxin exposure
  

What Causes Dementia?

Dementia refers to progressive cognitive decline from underlying diseases such as:

• Alzheimer’s disease
  
• Vascular dementia
  
• Lewy body dementia
  
• Frontotemporal degeneration
  

Research from Apollo Health (Bredesen protocol) highlights contributors such as:

• Glycotoxicity (insulin resistance)
  
• Neuroinflammation
  
• Toxins (mold, metals, chemicals)
  
• Nutrient depletion
  
• Sleep disorders
  
• Oral pathogens
  
• Chronic infections
  

Addressing these factors early can slow, halt, or sometimes reverse decline.

How Functional Medicine Differentiates the Two

At Insight Functional Health, your evaluation may include:

1. Cognitive screening (MoCA and/or CNS Vitals)
   
2. Detailed history of triggers, sleep, infections, stress, hormones, toxins
   
3. Metabolic testing (glucose, insulin, lipids, inflammation markers)
   
4. Hormone & thyroid evaluation
   
5. Nutrient status (B vitamins, ferritin, omega-3s, magnesium)
   
6. Root-cause testing (gut analysis, toxins, viral reactivation) only if appropriate
   
7. Brain-health protocols based on Bredesen ReCODE 2.0 and precision medicine
   

This approach helps distinguish temporary fog from patterns suggesting early cognitive impairment.

When to Worry

You should seek evaluation if you notice:

• Progressive memory loss
  
• Difficulty with everyday tasks
  
• Getting lost in familiar places
  
• Major personality or behavior changes
  
• Word-finding difficulty that worsens over time
  

Seek urgent evaluation for:

• Sudden confusion
  
• Severe headache with neurological symptoms
  
• Weakness or numbness
  
• Vision changes or slurred speech
  

What We Can Do

Dr. Sattah uses a personalized, brain-health approach that focuses on improving how your body produces energy, manages stress, and protects your brain over time. Depending on your needs, this may include:

• Nutrition strategies to support steady energy and blood sugar
  
• Support for the mitochondria (your cells’ energy centers)
  
• Improving sleep quality and circadian rhythm
  
• Balancing hormones when they are contributing to symptoms
  
• Calming an overactive stress response
  
• Supporting detox pathways when appropriate
  
• Restoring gut-brain communication
  
• Evaluating infections or toxin exposures when clinically relevant
  
• Using your genetics to guide care—identifying how your body is wired to respond to nutrients, stress, inflammation, and toxins so recommendations are tailored specifically to you
  

This approach is informed by the Bredesen ReCODE 2.0 protocol, which addresses over 36 biological factors known to influence cognitive health and uses personalized strategies to support brain resilience.

Suggested Additional Sources for RECODE 2.0 & Research

• Dr. Dale Bredesen — The End of Alzheimer’s Program (RECODE 2.0 overview)
  
• Peer-reviewed paper: Reversal of Cognitive Decline: 100 Patients — https://www.apollohealthco.com
  
• True Health CPM (Bredesen-trained clinicians) — https://www.truehealthcpm.com
  
• Journal of Alzheimer’s Disease — Precision medicine approaches
  
• PubMed — Search terms: "Bredesen protocol", "metabolic cognition", "precision medicine dementia"
  

Sources Cited

• Apollo Health (Bredesen ReCODE framework) — https://www.apollohealthco.com
  
• True Health CPM — https://www.truehealthcpm.com
  
• Institute for Functional Medicine — https://info.ifm.org
  
• NIH / NCCIH — https://www.nccih.nih.gov
  
• Cleveland Clinic — https://my.clevelandclinic.org/health/diseases/9175-dementia
  
• PubMed — https://pubmed.ncbi.nlm.nih.gov
  

Medically reviewed by Dr. Anna Sattah, MD, IFMCP
 Insight Functional Health — serving patients in Silver Spring, MD
 Concerned about brain fog or memory changes? Book your visit here.
 Learn more about our Functional Medicine approach or explore Cognitive Decline support.
 About Dr. Sattah

This content is for educational purposes only and does not replace personalized medical evaluation.