What Does Mold Do To Your Brain?

With the pace of modern construction and the transition to the use of drywall as a go-to building material, rates of indoor fungal growth are on the rise. Climate humidity levels can affect indoor dampness levels. However, the WHO has estimated that dampness in Australia, Europe, India, Japan, and North America is a problem in 10-50% of dwellings. The estimate for fungal growth in North America is consistent with that at 15-40% of homes.  These are no small percentages! 

Many people know that mold causes breathing issues, such as asthma. Still, the general population is unaware that mold releases mycotoxins, which can be a neurotoxin, causing significant, and in some cases, lasting effects on the brain. 

While the general population accepts that indoor mold growth can make a person sick, the usual assumption is that breathing issues are the primary and perhaps sole symptom.

Do you suspect that there might be mold in your house? We can help!

Or, perhaps, someone might allude to a “little allergy” to mold. The truth is biotoxin illness is much more severe and can affect all body symptoms. As we discussed in a previous article, “What is CIRS?” in the case of mold illness the body responds to the mycotoxins created by mold. These mycotoxins cause the deregulation of the immune system, hormonal imbalances, and neurological dysfunction. This article will focus on the neurological dysfunction caused by mold exposure. 

Mold is a Neurotoxin 

The general definition of a neurotoxin is a substance that alters the structure or function of the nervous system. In a recent article, “What are Mycotoxins?”  we did a deep dive into what mycotoxins are, their role in mold illness, and the effects of specific mycotoxins. In short, mycotoxins are the toxins released by a fungus (mold). These toxins can be neurotoxic, affecting the brain and nervous system, especially for those individuals who do not have the genetic ability to detox mold properly. That being said, these mycotoxins can be pretty powerful (and not in a good way!) and have the ability to make anyone sick. 

Potential Symptoms

Biotoxin illness causes a wide range of severe symptoms and is often mistaken for other chronic diseases. For this reason, awareness is crucial, and in that spirit, here at CMA, we make a point to list mold illness symptoms often. We want you to know you are absolutely not crazy. In some instances, one person in the household may not have any symptoms, while another person has a variety of symptoms across multiple body systems. Every case of biotoxin illness is unique.

  • Respiratory (asthma, sinus issues, earaches)
  • Anxiety and depression
  • Irritability, “mold rage.” 
  • Ice pick pain 
  • Light sensitivity
  • Blurred vision 
  • Red eyes 
  • Tearing
  • Cough
  • Shortness of breath
  • Abdominal pain 
  • Short term memory loss 
  • Morning stiffness 
  • Muscle cramps
  • Heart palpitations 
  • Slow wound healing 
  • Sweats, especially night sweats
  • Trouble regulating temperature 
  • Ringworm and other fungal rashes 
  • Problems with eyesight 
  • Dark circles under eyes 
  • Food sensitivities 
  • Migraines and other headaches 
  • Nightmares 
  • Insomnia 
  • Hair loss 
  • Decreased learning of new knowledge
  • Confusion

Neurological Symptoms

The mycotoxins released by mold spores irritate the body, causing it to launch an immune response. This ongoing immune response causes chronic inflammation, leading to multiple neurological symptoms, including. The most prevalent symptoms in cases of biotoxin illness are cognitive impairment, chronic fatigue, mood issues, and insomnia. 

Cognitive Impairment AKA “Brain Fog”

Brain fog is described as forgetfulness, slow response time, loss of words, trouble concentrating, and overall loss of mental clarity. Often, this is one of the primary symptoms described; for some people, the feeling can be instant upon entering a water-damaged dwelling. This symptom can affect the quality of life and financial life, as some mold-sick patients describe having trouble working. Brain fog can be a dangerous symptom. For example, a house fire is possible if short-term memory is affected while cooking. This is yet another example of how a moldy home can rapidly snowball into a big problem. 

Chronic Fatigue 

One of the symptoms our clients tell us about the most is unrelenting chronic fatigue. Patients do not wake up rested, have trouble getting out of bed in the morning, and require frequent naps to do basic tasks. Usually, when they come to us, they have an idea that their home might be moldy but still aren’t sure until we perform testing. A 2013 study found that mycotoxins were present in 93% of cases of chronic fatigue syndrome. It is now widely accepted that mold exposure can cause chronic fatigue syndrome. 

Mood Issues (Depression, Anxiety, Paranoia, Psychosis)

A 2019 study entitled “Mold inhalation causes innate immune activation, neural, cognitive and emotional dysfunction” identified the link between the immune response and increased stress response to auditory cues in mice. The researchers determined that mold creates a cascade of neurological issues, including depression and anxiety. Anecdotally, this is something that our CMA clients tell us about. It is challenging to manage a physical illness that inhibits your ability to handle stress while also dealing with the financial ramifications of remediation and temporary, or in some cases permanent, relocation. 


The neurotoxic nature of mold can impact our sleep health. The mycotoxins released by mold impede our circadian rhythm. A 2020 study concluded that mold exposure at work or home increases insomnia, snoring, and excessive daytime sleepiness. We have also heard this reported amongst almost all of our clients. 

Neurodegenerative Diseases 

Neurotoxins and mycotoxins have been implicated in cases of certain neurogenerative diseases. This requires more research to know the exact links, inflammatory domino effect, what symptoms are from mold exposure, and what is separate from that. However, with enough prolonged exposure, it has been proven that cases such as Parkinson’s are a potential consequence. 


To address the above neurological symptoms of mold, it is essential to treat mold holistically. In the body, treating the toxicity, inflammatory immune response, fungal infections (or coinfections) caused by mold exposure, and in some cases, an actual mold allergy. Furthermore, it is impossible to address the toxicity in the body without first addressing it in the home or workplace. 

Of the many horrible consequences of mold, the neurological symptoms that we have witnessed in our clients are the most devastating. As a company, empathizing with your story is part of our mission. We are here for you and encourage you to help us raise awareness on this serious issue. 

Find Us on Social 

Has mold affected your brain? We’d love to hear your story and help pass your story on to help others. Please find us on social and share your story and any tips with us! 

For more information about mold, or if you are interested in learning how to face life’s challenges with mold sickness, please follow us on Instagram and Facebook. If you have any questions or comments, feel free to leave them in the comments below or on our social media. 

And, of course, please book your inspection today!  While we are always sorry to hear of anyone with a mold issue, we look forward to sharing our experience, insight, and resources with you! 


1. Wang J;Janson C;Lindberg E;Holm M;Gislason T;Benediktsdóttir B;Johannessen A;Schlünssen V;Jogi R;Franklin KA;Norbäck D; Dampness and mold at home and at work and onset of insomnia symptoms, snoring and excessive daytime sleepiness. Environment international. Accessed September 29, 2023. https://pubmed.ncbi.nlm.nih.gov/32272294/.

2. Brewer JH, Thrasher JD, Straus DC, Madison RA, Hooper D. Detection of mycotoxins in patients with chronic fatigue syndrome. Toxins. April 11, 2013. Accessed September 29, 2023. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3705282/.

3. Harding CF, Pytte CL, Page KG, et al. Mold inhalation causes innate immune activation, neural, cognitive and emotional dysfunction. Brain, behavior, and immunity. July 2020. Accessed September 29, 2023. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7231651/.

4. WHO guidelines for indoor air quality: Dampness and mould. World Health Organization. January 1, 1970. Accessed September 28, 2023. https://apps.who.int/iris/handle/10665/164348.

5. SA; SSRT. Assessment of the aerosolization potential for fungal spores in moldy homes. Indoor air. Accessed September 28, 2023. https://pubmed.ncbi.nlm.nih.gov/15500633/.

6. Neurotoxin. Encyclopædia Britannica. Accessed September 28, 2023. https://www.britannica.com/science/neurotoxin.

Andersen B, Frisvad JC, Søndergaard I, Rasmussen IS, Larsen LS. Associations between fungal species and water-damaged building materials. Applied and Environmental Microbiology. 2011;77(12):4180-4188. doi:10.1128/aem.02513-10