How Do You Test for Mold Toxicity? Bloodwork for Mold Exposure & Other Tests

Written By


Expert Reviewed By

Dr. Lauryn Lax, OTD, MS

Dr. Lauryn, OTD, MS is a doctor of occupational therapy, clinical nutritionists and functional medicine expert with 25 years of clinical and personal experience in healing from complex chronic health issues and helping others do the same.

Test For Mold Toxicity - A Doctor Taking Blood Sample From A Patient To Test For Mold Toxicity

How do you test for mold toxicity? Unfortunately, most conventional medical doctors and average home inspectors won’t be able to help you. You need a mold-literate practitioner and environmental professional.

Read on to discover how you test for mold toxicity, including home testing, bloodwork for mold exposure and my other favorite tests.

My Mold Story

Test For Mold Toxicity - Lab Tests

I Don’t Feel Good… 

Less than 24 hours into my brand new, $3000 month (for 600 square feet), shiny condo rental at the Independent  in the middle of downtown Austin, I was sick. Real sick. Like vomiting, brain fog, seeing spots, whole-body-tingling sick.

What was supposed to be an escape from mold turned into the complete opposite—a mold vortex.

I (semi) slept that first night in my brand new condo on my brand new couch, with my head outside the only door “out” of the unit on the balcony.

What the heck? Mold? In here? 

The thing is no one saw it (including me). But I felt it.

Nevertheless, I chalked it up to be something else. VOCs? Off gassing from the engineered wood? The formaldehyde on the cabinets? Lack of air purification? 

I wrote an e-mail to the property managing company to inform them of my situation, just in case we’d need something in writing later… 

To remedy the situation, I hired the maintenance man to remove the cabinet doors in the kitchen and painted all the wood with a “stop off-gassing” paint I found on Amazon. I sprinkled coffee grounds on paper plates and paper towels and laid them throughout the condo. I put 2 air purifiers in every room. I bought toxin-eliminating spider plants and Peace Lily’s and ran my essential oil diffuser—lemon balm. I hired a local mold inspector to come check it out. He didn’t “see” anything.

But still, I felt sick. Throw up sick.

The third night, I slept on the balcony on my couch cushions. Then on nights four and five, I snuck up to the swanky condo media room at midnight and slept on one of the big leather theater chairs.

I’d signed a 12 month lease and I was determined to make it work gosh darn it.

But things didn’t get better. They just got worse. By day six, I couldn’t breathe. Literally. My lungs weren’t having it. That night, I slept in my car.

Why does outside on a balcony or in my car feel better than in my $3000 brand new condo?! 

By day seven, I was outtie. I could not take it. My body could not take it. Something was not right. 

I quit. Told the property management company something was not right. I’m not a quitter. But my health was not worth it. I begged for them to let me go. My doctors wrote letters. I shared articles and research about what I thought could be going on. They turned the other cheek. Said if I wanted out, I owed them two more months of rent plus the full month’s rent I’d already paid for the total two nights I was actually able to sleep in the condo.

The next week, the condo flooded. The entire building flooded. A pipe burst on the 23rd floor—the floor my unit had been on. A leak that had been there for awhile.

My body knew it. It felt it—something wasn’t right.

My sixth sense saved me. 

Do You Have Toxic Mold? 

Test For Mold Toxicity - A Doctor Talking To A Patient

Do you have toxic mold in your home or your body? That is the question.

Unfortunately, mold is not always seen with the naked eye. Rephrase that: Mold is often not seen with the naked eye. Nor is it always “caught” on traditional lab testing. Rephrase that: Mold illness is never caught on traditional lab testing.

This is why proper testing—both with the proper assessments for your home and your body, as well as working with a mold-literate practitioner is essential to get a complete picture of what is going on “under the hood.”

In this article, we’re going to chat how to test for mold toxicity in your home and your body. 

How to Test for Mold Toxicity in Your Home

Test For Mold Toxicity - A Inspector Testing The Wall

The toxic condo home that made me sick realistically had a mold issue the entire time I lived there. It just took me getting super sick to realize it.

The culprit? Black mold behind the beautiful concrete walls and permeating mycotoxins throughout the home thanks to the humidity that had built up in the home during its 6 months on the market—no AC turned on.

As previously mentioned, at least 1 in 2 homes has water damage and, consequently, mold accumulation. Our homes are made out of mold food itself (wood). Couple this with countless other homes that sit in 50 to 60% humidity—like Austin, Texas in the heat of summer; as well as people who have homes full of mycotoxin infested items (furniture, clothing, books, upholstery) and you’ve got the perfect storm for toxic mold.

Mold is everywhere. And mold is a normal part of life. Toxic mold however is not normal. It is toxic.

Unfortunately, testing the home to find toxic mold, much less the source, is not always easy, especially since often times toxic mold can be hidden inside the walls and flooring, especially in brand new construction homes. This is why both a comprehensive testing approach, combined with attention to the patient’s mold signs and symptoms (or lack thereof) is essential to know if mold or other biotoxins are present.

The Problem with Most Home Tests for Mold

Call most mold inspectors in your city, and ask them what type of mold testing they do.

Nine times out of 10 they will tell you: “Air sampling.”

Newsflash: Air sampling is the least sensitive marker for mold, especially toxic mold.

This is because mycotoxins—the toxic mold spores from mold—are heavy. They fall to the ground, collect in dust. Air sampling won’t “catch” these guys unless you have a really, really large toxic load in the whole home.

Additionally, many traditional home inspectors often fail to “catch mold” because they are simply looking for mold with the naked eye. But remember: mold is not always seen with the naked eye. It’s hiding in walls, flooring and HVAC systems too. Many average mold inspectors, unaware of the nuances of testing, will come to your house, look, and if they don’t see anything visually black on the wall, growing, they may feel you, “You don’t have a mold problem.” If more mold inspectors conducted proper mycotoxin testing (or actually knew what mycotoxins are), or if they cut into the walls and floors in homes, we’d have a front-page-news huge housing crisis on our hands. 

Top Home Mold Test Recommendations 

My favorite home mold tests include:

  • ERMI Dust Sampling
  • Indoor Environmental Professional (IEP) Inspection
  • Canary Testing 

I help my patients figure out the best companies and professionals to connect with for home testing as we work together. 

ERMI Dust Sampling

To date, the best initial screening that you can do at home for mold is “surface” or “air PCR” (polymerase chain reaction) testing—also referred to as “ERMI testing.”

The ERMI test was developed by the Environmental Protection Agency as a means of determining the relative “moldiness” of a home compared to a group of reference homes that do not have mold. This type of testing involves collecting possible mold samples with a dust cloth kit on surfaces where you suspect mold may be present. The cloth is able to pick up mold DNA on the surfaces of walls, furniture and places it may be, as well as the air. After collection, you or the mold inspector send it back to the lab for testing and mold identification under a microscope.

Some people claim that mold plate testing can work too, but keep in mind, it is not very sensitive. Mold spores differ in weight, density, and air flow characteristics, so some types are more likely to settle on the plates than others. Sticky molds that often appear near water damage, like black mold, may end up evading the plates completely.

Note: ERMI results will not tell you every single species, crevice or corner of your house that has mold. Results are still limited since they only evaluate the areas where you take a sample.  Testing is best to give you an idea of patterns and what types of mold may be present. 

Indoor Environmental Professional (IEP) Inspection

Test For Mold Toxicity - A Inspector Doing Indoor Environmental Professional Inspection

Not all mold inspectors are created equal. Many mold inspectors do not use in-depth, accurate testing methods. If you call up a local mold inspector and ask him to come assess your property, he will probably do a visual inspection and take some air samples, but on their own, they are not enough. Air sampling does not allow identification of particular species and does not easily detect toxic mold spores.

To accurately assess your exposure, the best practice is to hire a mold inspector, specifically an “IEP” (indoor environmental professional), who is familiar with proper testing methods (ERMI with EPA validated methods).

Do your research. Visit (ACAC is American Council for Accredited Certification) and look for “Certificants” in your area with one or more of the following certifications:

  • CCIEC, council-certified indoor environmental consultant;
  • CMI, council-certified microbial inspector;
  • CMC, consultant
  • CIAQP, certified indoor air quality professional

A good mold inspector will walk your property and be aware that the inside and outside can be equally affected; they may ask you questions about your health or timeline of mold exposure; they will know what ERMI testing is; if they run air sampling, they will send it out to a lab to be analyzed over a series of hours (not minutes); and they may have even heard about mold toxicity illness.  A good mold inspector also will not discount the fact that mold can occur in new construction. New construction is rarely suspected as a hotbed for mold, but don’t be fooled. Moldy drywall after new construction is particularly common. Unfortunately, many mold specialists claim they test mold, but do not utilize in depth type of testing, often missing the lingering root causes of toxic exposure.

Canary Testing 

A running joke in the mold world is that many of those who get really sick with mold toxicity develop a sixth sense—the ability to be a “canary in the coal mine”, the ability to sense mold in the environment, no formal testing needed.

That is me. My body is a human “mold detector” instead of a metal detector. Put me in a moldy or mycotoxin-rich environment and my chest closes up, my breath shortens, my fingers get tingly, my head feels heavy. I sometimes see spots. This can happen anywhere—a home, worshipping at church, shopping at Anthropologie. In fact, there are certain Anthropologies and other retail stores I will not go in. They are toxic—and everything in the store is toxic because of it. Not everywhere has toxic mold, but a lot of places do.

Prior to mold illness, I didn’t realize I had this “superpower,” but then again, I was always sensitive. Sensitive to medications, supplements, coffee, foods, hurt feelings, others’ opinions of me. I was intuitive—I could read people, situations, my body.

“Moldies” are often naturally super sensitive people. A super power in and of itself. In fact, my canary sixth sense is what has helped keep me “safe” in the world post-mold illness.

If there is one thing I’ve learned through mold illness, it is to trust your gut. Stop doubting yourself so much. Listen to your body. We all have an innate inner wisdom, an intuition that is there to protect us and keep us in “homeostasis” (balance). Most people simply don’t listen. 

How to Test for Mold Toxicity in Your Body 

Mold “workup” in the body is a bit more complex than running a throat swab to see if you have strep throat. It entails putting together a “complete picture” with various specialty labs along with clinical evaluation of symptoms and health history.

The top tests I run in clinical practice include:

  • Mycotoxin urine test
  • Visual contrast sensitivity test
  • Specialty bloodwork for biotoxin markers
  • MARCoNs testing
  • Other exposures and infections

Most conventional doctors are not trained or aware of the workup for toxic mold exposure. This is where working with a functional medicine practitioner comes into play. 


Test For Mold Toxicity - Mycotoxin Urine Test

A mycotoxin urine test is a one-day sample collection you can do at home, then send off to a lab to interpret results.

A positive urine test, more often than not, confirms the diagnosis of mold toxicity. Mycotoxin urine testing also tells you, with more precision, which specific toxins are involved so we can be more precise as to which binders will be clinically helpful.

At the time of this writing, there are three primary types of mycotoxin urine testing and only a handful of lab companies to order from including:

  • Mass Spectrometry

Great Plains Laboratories

  • ELISA Testing

Real Time Labs

Vibrant Health

  • Microarray Analysis

Vibrant Wellness

Mass spectrometry is theoretically more accurate and reproducible but more specific as to what is measured (so sometimes it can miss things). ELISA testing often picks up on residual “metabolites” (byproducts) of a wider variety of mycotoxins. And microarray analysis not only tests for over 30 different mycotoxins, but other biotoxins (with big words) like fumonisins, patulin, nivalenol and diacetoxyscirpenol. Due to these testing methodology differences comparison between is not possible. In clinical practice, all give excellent and useful information and if possible, I at least run two (often Mass Spectrometry and ELISA).

There are a few caveats to know about mycotoxin urine testing.

First, in order to get accurate results from a mycotoxin test, you may need to perform a challenged urine testing (especially if you are a “bad detoxer” like me and do not easily clear out toxins). Basically, a “challenge” test helps mobilize mycotoxins that may be trapped in tissues or housed in the liver and gallbladder.

Seven days prior to collection, use 500 mg glutathione twice daily for seven days, collecting urine on seventh day. If you cannot take glutathione or you’re super sensitive to supplements, mobilize toxins through sweating: use the sauna, a hot bath or hot tub at least one to two days prior to collection. Also, if you are taking binders (like charcoal or clay), stop all binders 3 days prior to collection of the urine specimen. 

Be careful with the challenge process. It can (and does) mobilize toxin faster than some folks can process toxins. Anything that mobilizes mold toxins may inadvertently pull more toxins into the  body than it is capable of dealing with. Go low and slow. If an exacerbation of mold toxic symptoms occurs with glutathione or sauna, stop it and collect urine immediately.

It is vital to understand that urine testing reflects not only the presence of mycotoxins, but also the body’s ability to mobilize and release those toxins. Something interesting I observe in many patients after their first mycotoxin urine test, once mold treatment has ensued and patients improve, it is very common for the next urine  test sample to reflect much higher mycotoxin levels and a more accurate test baseline. They are detoxing better by that point (as long as symptoms are also improving, not worsening—reflecting mold reexposure)!

Lastly, be aware: Some clinicians argue, “But doesn’t everyone have mycotoxins in their urine?!”, claiming that urine testing is invalid. However, that is not what I’ve seen in clinical practice—mycotoxin levels as well as mold toxicity symptoms are commonly present in those with positive mycotoxin test results. One study by Great Plains Labs of 82 controls (no known mold exposure) and 103 patients with known mold exposure, showed that, while 51% of controls do have ochratoxin (and other toxin levels were trivial), they only averaged 1.6 ng/g while 85% of mold patients averaged greater than 18.

That said, mycotoxin urine testing is not the “end all, be all” for mold toxicity. Some positive urine tests can pick up the molds you consume in foods. For others,  I still see patients who are almost positively mold toxic with negative tests often due, once again, to their inability to detox and excrete mycotoxins as well as the possibility that their test is not measuring the toxin that is causing symptoms (like Wallemia). This is where other tests, symptom and mold exposure history, and possible empirical mold treatment can come into play. 


The Visual Contrast Sensitivity test (VCS) is a quick triage test that can be done online at home to assess for mold toxicity, Lyme disease and mercury toxicity. It is not specific, but has been used by thousands of patients and clinicians to evaluate the neuroinflammation often sparked from mold toxicity. 


The following labs are available via Lab Corp and Quest. 

TGF Beta 1 (Bloodwork)

Normal Range:  <2380 pg/ml

High TGF Beta 1 levels is considered to be a mold-specific marker.

If you don’t get the TGF Beta 1 level down in chronically ill patients, you’re unlikely to succeed in turning their cases around. So, it’s useful to know why TGF-Beta 1 levels become elevated and what to do about it.

TGF Beta 1 spikes when the immune system is up regulated and out of balance, especially when Th1 cells are “down”.

There are two primary immune cells: T-helper 1 cells (Th1)  and T-helper 2 cells.

Th1 cells stimulate the cell-mediated immune response–the immediate immune response that  releases cytokines to help combat immediate immune triggers to things like allergens, toxins and bacteria. Th1 cells drive cytokines to immediately fight and defend against pathogens that may try to attack the host.

Th2 cells, on the other hand, are like the “backup” bouncers. They stimulate the humoral immune response—an immune response that happens when your body (memory B-cells) “remember” a trigger, like mold.

When Th2 cells are stimulated, they create antibodies (as seen in autoimmune disease) and attack self-tissues as they fight to eradicate pathogens like mycotoxins and environmental triggers. This is why a person who is constantly being exposed to mold or living in a mycotoxin (toxic) environment can’t get better until they are out of there. The Th2 system continues to provoke mold symptoms, like brain fog, shortness of breath, gut distress and fatigue. Sort of like if a person with celiac disease (gluten allergy) is continually exposed to gluten.

Specifically, molds (and other ongoing immune triggers and excess stress) drive Th2 immune dominance because the Th1 system is constantly firing cytokines (especially Interleukin C2) to try to fight against mold. In other to keep up, Th2 cells work harder. Consequently, TGF-beta 1 level goes up.

Clinical Pearls

TGF Beta 1= Inflammation

Being Th2 dominant doesn’t just mean you have a mold issue. Since TGFbeta is driven up by inflammatory cytokines, you need to work with your clinician to figure out why the Th2 dominance is there, rather than assuming that just mold or Lyme is the reason. For example, formaldehydes and other toxins in the home, excess oxidative stress (like overtraining), a chronic infection (parasite, Lyme, etc.) or eating inflammatory foods may also be part of the issue.

What to do about it?

You need to shut down the Interleukin Cytokine up regulation to help decrease TGF Beta 1.

This involves inhibition of Interleukin-4 by using natural anti-histamines like perilla seed and boswellia plus mast cell histamine release inhibitors, especially flavonoids (the keys are luteolin, quercetin, rutin). You can also use N-Acetyl Cysteine to break up inflammatory mucous and support natural glutathione production, as well as bromelain to break down the Mitochondrial DNA (mtDNA) released by mast cells and supporting aldehyde dehydrogenase (a mitochondrial support) with B2, B3 and molybdenum. Lastly, to “cool down” Th2 dominance, astragalus helps.


  • Perilla seed
  • Boswellia AKBA
  • Flavonoids (luteolin, quercetin, rutin)
  • NAC
  • Bromelain
  • B2, B3 and molybdenum
  • Astragalus

MSH – Melanocyte Stimulating Hormone

Normal Range:  35-81 pg/mL

In mold illness, Melanocyte Stimulating Hormone (MSH)  will be low in over 95% of patients. MSH is a master regulator in the hypothalamus. The downward effects of low MSH results in mold toxicity symptoms spiraling out of control as well as suppressed levels of cortisol and ACTH the longer exposure to mold goes on (resulting in fatigue and low energy). MSH is related to melatonin production and circadian rhythms (i.e. sleep-wake cycles), disrupting sleep. Endorphin production and sex hormone production is suppressed, leading to loss of pain control, Fibromyalgia, anxiety and low libido. Low MSH also affects GI absorption resulting in diarrhea and ‘leaky gut’. Though not Celiac Disease, some patients will develop Celiac-related antibodies (e.g. anti-gliadin IgG and IgA).

MBL (Mannose-binding lectin)

Normal Range: 800 to 1000 ng/ml

Mannose-binding lectin (MBL) mediates the innate immune response. In people with chronic infections (such as chronic mold and fungal overgrowths) have higher levels of serum MBL. MBL markers might partially explain why some mold patients are more treatment resistant than others.


Normal Range:  0-2830 ng/ml

C4a is an inflammatory marker that looks at innate immune responses in those with exposure to mold.  High C4a means your immune system is in overdrive and it yis working hard trying to clear out toxins and pathogens. Elevated C4A levels affect the body by: inhibiting capillary perfusion and leading to fatigue, brain fog and inflammation.

An initial rise of C4a in blood levels is seen within as little as 12 hours of exposure to biotoxins, and sustained elevation is seen until definitive therapy is initiated.


Normal Range:  85-332 ng/mL

High MMP9 is common in mold toxicity. MMP9 is an enzyme that is involved in the breakdown of extracellular matrix in normal physiological processes (like reproduction, and tissue remodeling), as well as in disease processes. In mold illness, MMP-9 delivers inflammatory components of blood into spaces into various organs (brain, lung, muscle, peripheral nerve and joint), up regulating tissue destruction. His MMP9 shows high Th1 inflammatory cytokine activity. 

HLA-DR Testing

About 25% of the population is genetically susceptible to chronic mold illness. Three quarters isn’t. You can evaluate your Human Leukocyte Antigens (HLAs) genes to see. Human Leukocyte Antigens (HLAs), are found on the surface of nearly every cell in the human body. They help the immune system tell the difference between body tissue and foreign substances.

The genetically susceptible will test positive for the HLA-DR “mold genes” (specifically 7/2 or 3/53, 13/6/52A, B & C, 17/2/52A, 18/4/52A, 4/3/53, 14/5/52B, 11 or 12/3/52B), making them more susceptible to mold toxicity and impaired mold detoxification. Running a genetic panel is another test to paint the bigger picture for mold toxicity. Although, be encouraged: just because you have the HLA-DR gene(s) does not mean you cannot recover from mold toxicity.

Currently, this testing is only done through LabCorp. 


MARCoNS stands for “Multiple Antibiotic Resistant Coagulase Negative Staph” and is a condition often seen in individuals with a history of mold exposure involving the colonization of staph infection in the sinuses. This test involves a simple nasal swab that can be sent back to a lab for interpretation. A positive result simply helps further contribute to the mold toxicity diagnosis, but eradication or treatment of MARCoNS is not necessarily the “end all, be all” for kicking mold toxicity by any means. A positive MARCoNS test is sort of like a positive SIBO or candida test when a person actually has an underlying gallbladder and low stomach acid and digestive enzyme issue (contributing to bacterial and yeast overgrowth)—a symptom.


Mold illness or CIRS stems from more than just mold! Don’t forget about the following exposures:

  • Lyme disease (from ticks and fleas) and Co-infections (Bartonella, Babesia, Rickettsia, Mycoplasma)
  • Ciguatera (food poisoning from fish)
  • Brown Recluse Spider Bite
  • Scorpion Bite
  • Cyanobacteria (found in water, like lake water)
  • Yersinia Enterocolitica
  • Chlamydophilia Pneumoniae
  • Viruses (Cytomegalovirus, Parovirus, Epstein Barr, Herpesvirus)

A history of exposure is essential for the diagnosis of CIRS, however it can be difficult to pinpoint at times, especially if a person does not recall being bit by a tick or contracting food poisoning for example. Some markers (like Lyme) can also be difficult to diagnose via bloodwork as most labs do not use the gold standard lab test methodologies for work up.


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