Mold and Mycotoxin Illness: Should I Be Concerned?

Given all of the information circulating now about the potential challenges with mold and mycotoxins, I felt it was critically important to provide you with an accessible summary seeking to answer these key questions.

  1. What exactly is mold? and mycotoxins? Do they pose a universal threat to all of us?
  2. How exactly do mold and mycotoxins cause dysfunction in the body? Are there any hallmark symptoms associated with mold toxicity?
  3. Are there any effective methods of testing for mold and mycotoxins either in my home or in the body itself?
  4. Are there any reasonable and well-agreed upon clinical treatments for mold and mycotoxin illness?

What I offer here is my best scientifically informed summary of our current understanding about mold and environmentally acquired illness. We are in our earliest investigations about how mold and mycotoxins can cause dis-ease and no one I can assure you has it 100% figured out. With that let’s start the exploration!

What is Mold?

To best understand mold, we need a short biology lesson.

Mold is one of the major sub classifications of fungi. Fungi are eukaryotic microorganisms or organisms that have membrane-bound nuclei inside of their cells. We too are eukaryotic organisms and thus, are more similar to fungi than bacteria.

Fungi are classically separated into two groups based on their physical structures and reproductive methods.These two groups are molds and yeast. Yeast are single-celled organisms that reproduce by budding. Common yeasts include Candida albicans and a beneficial yeast probiotic known as Saccharomyces boulardii. Molds exist as multicellular organisms structured around filamentous elements called hyphae and reproduce via a method called apical extension. In addition to these two main classifications of fungi, we often speak of a third group of multicellular fungi with a fruiting body known as mushrooms. Molds and mushrooms utilize small spores to replicate and grow. These spores are living elements that are fairly resilient to external stressors, but are essentially dependent on water and moisture in the form of humidity to actively grow.

Like humans, fungi must take up carbon and nitrogen from the environment to maintain their cellular structures. Carbon is one of the essential building blocks of fats and carbohydrates and fungi use/consume a variety of carbohydrates, alcohols and fats to meet their carbon needs. Nitrogen is one of the essential building blocks of protein and nucleic acids (think DNA) and fungi obtain nitrogen from protein and other nitrogenous compounds in the environment. Fungi, you see, “eat” in a similar way as humans!

When you look at the structure of fungi, interestingly, we find that their cell membranes are very similar to our own. All humans have cholesterol in their cell membranes, while fungi utilize a similar sterol known as ergosterol. Of note, some of the antifungal medications capitalize on this difference in cellular structure, disrupting the production of fungal ergosterol instead of human cholesterol so that fungal cells cannot remain stable.

I share this short lesson in biology as a way to help demystify the perception that microorganisms such as bacteria, mold and yeast are somehow fundamentally different than humans and to dispel the perception that they are somehow playing by different natural laws. We as humans live in a symbiotic and commensal balance with microorganisms including viruses, fungi and bacteria present throughout essentially all cells and tissues of the body. Many healthcare providers, including myself, are beginning to argue that most of human dis-ease involves some form of perturbation to this complex ecosystem, and that we must be careful to live lifestyles and utilize treatments that honor the dynamic and wholistic balance of this “unseen” world.

What are Mycotoxins?

Mycotoxins are very small metabolites produced by certain molds. Unlike spores and the fungi themselves, these mycotoxins are not really considered “alive”, but rather products released from molds as a byproduct of their metabolism and interaction with the surrounding environment. Researchers have discovered, primarily through the study of animals, livestock and associated agriculture that these mycotoxins can exert very detrimental effects on animals as well as humans. Mycotoxins have been associated with damage to the nervous system, kidneys, immune system, liver and the genetic “instructions” – DNA itself. Almost all medical students learn in medical school that a mycotoxin known as aflatoxin produced by the mold Aspergillus can be a causatory element in the development of liver cancer. All forms of medicine agree you see, that mycotoxins can exert detrimental effects on humans, the challenges arise when we realize that it is not as simple as mycotoxin = “always bad in any amount at any time”.

Not all humans are similarly affected by even the same level of mycotoxin exposure, let alone the same mycotoxin itself. Numerous variables can contribute to someone’s susceptibility to environmental toxicity such as mold exposure including nutritional status, the health of the gut microbiome, liver detoxification – cytochrome P450 pathways, the function of the biliary tract, bowel movements, and overall immune balance. Just because one person living in a house with a high volume of mold does not show overt symptoms while another living in that same house is significantly debilitated does not mean that mycotoxins are not present as one of the contributory elements to the sick person’s state of dis-ease, it simply means that there are differential effects from the presence of these mycotoxins depending on an innumerable number of health factors. Similarly, having mold growth in your home or working environment does not guarantee you will be physically affected or show symptoms. To make things even more complicated, individuals can have symptoms and immune responses to mold spores themselves, typically within the naso-sinus and respiratory tract AND symptoms and immune responses related to the much smaller mycotoxins that can be present more extensively in various cells and tissues. The clinical picture can be quite complex!

Symptoms of Mycotoxicity or Mycotoxicosis

As you may have surmised, given the tremendous variety of mycotoxins, nearly all human cell types can be disrupted by the excessive or extended presence of mycotoxins. It is believed that mycotoxins exert detrimental effects on cellular function primarily by increasing cellular oxidative stress or reactive oxygen species (ROS). ROS are a normal byproduct (a form of exhaust so to speak) of our cellular metabolism, and we generally maintain a normal balance of ROS generation and elimination through our own antioxidant enzyme systems. In the face of various cellular stressors including psychological stress, excessive caloric and sugar intake or mycotoxin exposure, we can tip the balance of ROS generation and elimination so that we cannot readily keep up with all of the exhaust. The ROS can then begin to cause downstream havoc, damaging cellular structures such as the mitochondria and even DNA. If the cellular damage is severe enough, it can ultimately lead to the cell undergoing programmed cell death or apoptosis.

Because of the wide-reaching effects of mycotoxins on numerous cell types, many of the common symptoms of mycotoxicity are quite nonspecific and can be present as a result of many other root imbalances. This commonality of symptoms makes it very challenging for clinicians to not under or over diagnose mycotoxicity as a primary imbalance.

Many mycotoxins will cause irritation and symptoms affecting the eyes, ears, nose, and throat such as hay fever, allergies and chronic sinusitis. Others will provide challenges to the respiratory system that may manifest as sensitivity to fragrances or other volatile compounds, wheezing or a chronic dry cough. Clinicians are also beginning to recognize that many symptoms of imbalance in the nervous system such as cognitive impairment, dizziness, tremors and neuropathies could be related to mycotoxicity. Some of the leading clinicians in the field of environmentally acquired illness have suggested that symptoms such as electric-shock sensations and ice pick like neuropathic pain are more strongly indicative of mycotoxicosis, however, even these symptoms do not guarantee that mycotoxins are the root of one’s dis-ease.

Testing for Mold or Mycotoxins and Diagnosing Mycotoxicosis

Put simply, our tools for assessing mold growth, mycotoxin burden or human mycotoxicosis are in early clinical development. Like nearly everything in clinical medicine, the landscape is gray and we must be calculated and cautious when using new tools to assess potential root imbalances of dis-ease. While some individuals will arrive at a formal diagnosis of mold presence or mycotoxicity utilizing environmental testing or mycotoxin testing on human urine, the majority of patients arrive at the prospect of environmentally acquired illness such as mold toxicity because other integrative treatments such as diet, lifestyle, gut-based or immune modulating therapies do not lead to the complete resolution of symptoms. In my clinical practice, my suspicion for environmentally acquired illness such as mold toxicity is usually piqued when my patients persist with a myriad of challenging symptoms despite the implementation of robust dietary, lifestyle, and gut-based treatments. All of this being said, we do have a few clinical tools to help assess if mold and mycotoxins are related to one’s symptoms and dis-ease.

1. Symptom Questionnaires

Some of the most helpful clinical tools for exploring environmentally acquired illness are actually clinical questionnaires. Naturopathic physician Dr. Jill Crista provides a robust clinical questionnaire for assessing mold toxicity in her book: Break the Mold. The Institute for Functional Medicine provides trained clinicians with its own environmental toxicity assessment tool and there is a clinically validated environmental toxicity assessment questionnaire developed by Dr. Claudia Miller known as the QEESI that can be a helpful screening tool. Ask your clinician if you are concerned about environmental toxicity and consider starting with a clinical screening questionnaire.

2. Home Mold Assessment

Indoor environmental professionals (IEP’s) or building biologists can be helpful allies for performing rigorous assessments of a home or working environment looking for signs of water damage and potential mold growth. Some IEP’s also will recommend and perform testing for the presence of mold spores by sampling dust collected in the environment. I recommend if you are concerned about mold growth in the home, to invest in a building biologist or IEP to perform the assessment and testing themselves over doing it all yourself. The International Society for Environmentally Acquired Illness (ISEAI) has a helpful article to get you connected with the appropriately credentialed IEP, many of whom even offer virtual consultations.

3. Testing the Body

Testing the body for mycotoxins or mycotoxin related immune response is where things get really challenging. Dr. Ritchie Shoemaker was an early pioneer who identified a few immune markers that were commonly dysregulated in patients displaying signs of environmentally acquired illness. The problem with these immune markers is that they are quite expensive or impossible to obtain via common labs and even if the immune markers are dysregulated, it does not prove that mold or mycotoxins are the reason for the abnorma labs. Because of these challenges, I do not really recommend obtaining this type of testing at this time.

Outside of non-specific immune markers, there have emerged a few labs performing assessments for the presence of mycotoxins in the urine. Practitioners in the integrative medicine community are actively debating the best ways to utilize these tests such as to first diagnose mycotoxicosis or to track the effectiveness of treatment. Some clinicians recommend different preparatory methods prior to performing the urine testing to get the best assessment of mycotoxin and metabolite excretion in the urine. At this time, my best recommendation if you are working with a medical provider who utilizes urine mycotoxin testing is to ensure the specific intention and timing of the testing (initial diagnosis vs. treatment progression) and if a positive or negative result will actually change your clinical management. For example, if you have already found the presence of mold in the home and are displaying clinically correlative symptoms with an intention of remediating the home/treating yourself, it is certainly reasonable to pass on the investment in urine or mycotoxin testing and simply move forward with treatment. If mold testing in the home is inconclusive or you suspect no further ongoing mold exposure, then urine mycotoxin testing may be more helpful to direct clinical management.

Companies Offering Urine Mycotoxin Testing

  1. Vibrant Wellness
  2. Great Plains
  3. RealTime Labs

A Summary of Treatment

In the next few paragraphs, I offer a general treatment regimen for those concerned with environmentally acquired illness or mold toxicity. Individual treatment approaches and products will vary from person to person and I encourage you to explore these options with your medical provider.

1. Eliminate and avoid any on-going mold and mycotoxin exposure

This is the most critical and well agreed upon first step from any integrative clinician treating patients with mold toxicity. It can also be the most financially, emotionally and physically disruptive step depending on the extent of water damage and remediation required. In working with my patients, while I stress the importance of this step, I also acknowledge its complexity and the financial and practical burden it can place on an individual and their family. Do not skip this step, but at the same time, be gentle with yourself about this process.

2. Support the terrain with the fundamentals

All too often, after suspecting mold toxicity, it is easy to jump into very complicated and expensive treatments. Before moving into very methodical and financially demanding treatments, one should begin by prioritizing the fundamentals such as diet, lifestyle, sleep, stress management, social connection, self-discovery and play. As you can imagine, after discovering mold or mycotoxin presence in the home, many of these fundamentals can be markedly disrupted, leading to continued illness even after beginning to remove oneself from the primary exposure. We must support our bodies with nutrient dense food while providing “signals of safety” to our nervous systems as we are able through practices such as meditation, prayer and breathwork.

3. Supporting the GI Tract and motility

Depending on the clinician, treatment following steps 1 and steps 2 can diverge in any number of ways. I have found that it is very critical to support the health of the gut ecosystem and most specifically gut motility prior to pursuing any further mycotoxin “removal” treatments. We are coming to understand that some of the challenges posed by mycotoxins are mediated through a disturbed gut microbiome and disrupted gut barrier. Many clinicians will utilize various binders that seek to support the elimination of toxins including mycotoxins through bile/bile acids. Many of these binders that stay within the GI tract can negatively affect gut motility and actually cause worsening symptoms from reabsorption due to incomplete elimination. Spending time supporting the gut microbiome, the gut barrier and overall gut motility is a critical step as part of any mycotoxin specific treatment plan.

4. Supporting detoxification and cellular function

During step 4 is where I will typically recommend supports for the broader detoxification systems and augmentation to support cellular dysfunction. To ensure we do not skip the fundamentals, I will reiterate the foundational minimization of other environmental toxins from cosmetic products, cookware, air and water. From here, one can often use certain dietary fibers, sauna and lymphatic type therapies including massage to promote toxin elimination. Various flavonoids, nutrients and herbs to mitigate excessive cellular oxidative stress can also be applied at this time. I often think of this as the final preparation before any form of antifungal treatment outlined in step 5.

5, Utilizing anti-fungal treatments

Step 5 can be broadly considered as the use of any antifungal treatment including herbs or prescription medication. The antifungal therapies can include intranasal or sinus treatments to address intranasal colonization as well as topical and oral preparations. It is critical in my opinion to work with a well-trained provider should you pursue any antifungal treatments. There are a wide variety of treatments and treatment approaches so be wary of any dogmatic approach to anti-fungal treatment. In addition, this step is not always necessary depending on the degree and timing of mold or mycotoxin exposures.


Given the state of our technologically driven modern society, we will likely continue to see an increased burden of environmental toxicity including mold toxicity. As clinical practice and laboratory testing methodologies improve, we will likely be able to identify those suffering from mycotoxicosis more quickly and treat individuals with more robust and minimally invasive therapies. We must be careful to find the right balance of awareness regarding our indoor environments that may harbor water damage or mold growth with the recognition that mold and mycotoxin exposure is not universally harmful. An iterative treatment approach that starts with informed clinical assessments followed by the implementation of foundational lifestyle treatments and support of the gut ecosystem before moving to more specific mycotoxin treatments will likely benefit those dealing with mycotoxicosis and prevent individuals from suffering unintended financial or medical harm.


McGinnis MR, Tyring SK. Introduction to Mycology. In: Baron S, editor. Medical Microbiology. 4th edition. Galveston (TX): University of Texas Medical Branch at Galveston; 1996. Available from:

Bennett JW, Klich M. Mycotoxins. Clin Microbiol Rev. 2003;16(3):497-516. doi:10.1128/cmr.16.3.497-516.2003

Wen J, Mu P, Deng Y. Mycotoxins: cytotoxicity and biotransformation in animal cells. Toxicol Res (Camb). 2016;5(2):377-387. Published 2016 Jan 7. doi:10.1039/c5tx00293a

Liew WP, Mohd-Redzwan S. Mycotoxin: Its Impact on Gut Health and Microbiota. Front Cell Infect Microbiol. 2018 Feb 26;8:60. doi: 10.3389/fcimb.2018.00060. PMID: 29535978; PMCID: PMC5834427.

About Rob Abbott, M.D.

Rob Abbott, M.D. is medical director and the functional physician for Resilient Roots: Functional and Evolutionary Medicine in Charlottesville, Virginia. He completed his family medicine internship with VCU-Shenandoah Valley in Winchester Virginia and is a graduate of the University of Virginia (U.Va.) School of Medicine where he served as a student ambassador for the U.Va. School of Nursing’s Compassionate Care Initiative, promoting resilience, compassion and self-care. He has completed additional training with the Institute for Functional Medicine, is a Kresser Institute ADAPT Level 1 trained clinician, and is an AIP Certified Coach. Rob approaches medicine from an evolutionary and functional perspective and practices what he calls “spiritually focused and evolutionarily informed functional medicine.” In his free time, Rob enjoys creative expression through writing, sharing blogs, poetry and podcasts through his website


  • What is the danger of others contacting Mycotoxciosus? Are friends (not sharing living quarters or personal items (clothing, sitting in the car, etc) susceptible to the illness? Can toxins ‘travel’ via air or touch the same object, transmit the spores or toxins in the amount needed to become ill? Thank you. A prompt reply would be greatly appreciated, as in your sharing the above information.

    • Mickey Trescott says

      Hi Hanna! These questions should be directed to a medical provider who specializes in mold illness, as this article is for informational use only. Best of luck to you!

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