How to Test for Mold in Your Body: A Look at the Methods

There is no single validated test that tells you whether mold is making you sick. The testing landscape is fragmented: some methods are well-established in mainstream medicine, some are experimental, and some are actively discouraged by public health agencies. What you should be tested for depends entirely on whether the concern is a mold allergy, an actual fungal infection, or exposure to the toxic byproducts molds produce, called mycotoxins. These are different clinical questions with different diagnostic tools, and the confusion between them is where most people get steered wrong.

Three Different Problems, Three Different Testing Paths

When people say they want to test for “mold in their body,” they usually mean one of three things: that mold spores are triggering allergic reactions, that a fungus has colonized tissue somewhere in their body, or that mycotoxins from a moldy environment have accumulated and are causing chronic symptoms. Each of these has a different level of scientific support behind its testing methods.

Mold allergy testing is the most straightforward. Allergists have been diagnosing sensitivity to fungal species like Alternaria, Aspergillus, Cladosporium, and Penicillium for decades using standard tools. Invasive fungal infection testing is well-validated too, though it applies mainly to people with compromised immune systems. Mycotoxin body-burden testing, the kind most heavily marketed to people worried about water-damaged buildings, is where the evidence gets thin and the controversy gets loud.

Urine Mycotoxin Testing and Why Experts Are Skeptical

If you have searched online for mold illness testing, you have almost certainly encountered labs offering urine mycotoxin panels. These tests use mass spectrometry to measure levels of specific mycotoxins in your urine and report back whether they fall above or below the lab’s own reference range. The pitch sounds scientific, and the technology behind the measurement itself is real. The problem is with the interpretation.

A German medical guideline, developed across multiple specialty societies, concluded that there are currently no useful and validated test procedures for mycotoxin-related clinical diagnostics in humans.¹ A separate German clinical guideline stated more directly that blood or urine tests for mold components or metabolites are generally not indicated as part of the medical evaluation of indoor mold exposure.² The CDC flagged this issue as well after investigating a case in which a commercial lab reported “positive” results for ochratoxin and trichothecenes in a patient’s urine, using the lab’s own cutoff values, and interpreted them as indicating an unusual level of mycotoxins in the body.³

The core issue is that no one has established what a “normal” range of urinary mycotoxins looks like in the general population, so calling a result “high” is essentially meaningless without that baseline. The labs set their own thresholds, which have not been validated against health outcomes. You can get a number back, but nobody can reliably tell you what that number means for your health.

Your Cereal Might Be the Reason You “Test Positive”

One of the most underappreciated problems with urine mycotoxin tests is that everyone ingests mycotoxins through food, every day. Grains, coffee, dried fruits, nuts, and wine all contain trace amounts of various mycotoxins because fungi are a normal part of agriculture. A study of 300 people in the United Kingdom found that the mycotoxin deoxynivalenol (DON) was detectable in nearly 99% of urine samples, and urinary levels rose in direct proportion to cereal intake. Wholemeal bread, white bread, pasta, and breakfast cereal were all independently associated with higher urinary DON.⁴ A study of Swedish adolescents found similar associations between grain-based food consumption and levels of DON, enniatins, and ochratoxin A in blood and urine.⁵

This means a “positive” urine mycotoxin result could simply reflect that you ate toast for breakfast. Without knowing how much of the detected mycotoxin came from diet versus environmental exposure, the test cannot distinguish between the two. Analytical chemistry has gotten remarkably sensitive, with some lab methods detecting mycotoxins at concentrations as low as 0.005 micrograms per liter of urine.⁶ That sensitivity is a double-edged sword: the instruments can find what is there, but finding it does not mean it is causing harm.

To make matters more complicated, different mycotoxins linger in the body for very different lengths of time. Ochratoxin A, for instance, has an extremely long half-life in humans, roughly 35 days, meaning a single dietary exposure can keep showing up in blood for months.⁷ A “positive” ochratoxin result at any given moment could reflect cumulative dietary intake from weeks ago, not an acute environmental crisis.

Testing for Mold Allergy

If your symptoms are respiratory (sneezing, congestion, worsening asthma, itchy eyes), mold allergy testing is the most established route and relies on the same diagnostic tools allergists use for pollen, dust mites, and animal dander. The two main options are skin prick testing and blood tests measuring specific IgE antibodies to mold species.

In skin prick testing, a tiny amount of mold extract is placed on the skin and the skin is pricked to let the allergen in. A raised bump indicates sensitization. Blood-based specific IgE testing measures the same immune response through a serum sample. In practice, the two methods sometimes disagree: skin prick tests tend to pick up mold sensitization more often than blood IgE tests. One study found that skin prick tests detected sensitization in about 54% of tested patients, compared to about 33% for serum IgE.⁸ Discrepancies also showed up in patients sensitized to multiple fungal species at once.⁹

One clinically useful finding is that specific IgE to a common mold test panel was significantly more frequent in people with confirmed mold exposure (about 41%) compared to unexposed individuals (about 17%), and exposed asthmatics showed the highest sensitization rates, around 55%.¹⁰ So for people whose asthma or allergic symptoms are clearly worse in moldy environments, IgE testing can help confirm the connection.

Why IgG Testing Is Not the Same Thing

Some labs offer IgG antibody tests for mold alongside IgE panels, and the two are often confused. IgG antibodies indicate that your immune system has been exposed to something and has mounted a response, but they do not indicate allergy. Nearly everyone has IgG antibodies to common environmental molds simply from breathing indoor and outdoor air. While IgG to specific fungi has some limited role in diagnosing hypersensitivity pneumonitis, a serious inflammatory lung disease caused by repeated inhalation of organic dusts, the same study that found IgE useful for mold exposure found that IgG to a mold mix panel was not a useful diagnostic marker for mold-related respiratory symptoms.¹⁰ IgG measurements can help confirm exposure in people who already have evidence of mold growth in their home or workplace along with hypersensitivity symptoms.¹¹ But the ubiquitous nature of fungi and the lack of specificity of fungal antigens limit the usefulness of IgG for pinpointing building-related illness.¹²

Testing for Invasive Fungal Infections

If the concern is that fungi have colonized tissue in the lungs, sinuses, blood, or elsewhere, the diagnostic approach is completely different from allergy testing or mycotoxin panels. Invasive fungal infections are a serious medical problem, but they overwhelmingly affect people with weakened immune systems: organ transplant recipients, people undergoing chemotherapy, those with advanced HIV, or patients on prolonged high-dose steroids. For most otherwise healthy people worried about a moldy apartment, an invasive infection is very unlikely to be the issue.

Two blood-based biomarkers are commonly used in hospitals. The galactomannan (GM) antigen test detects a component of Aspergillus cell walls, while the 1,3-beta-D-glucan (BDG) test detects a sugar found in the walls of many fungal species. In a study of nearly 300 patients with blood cancers suspected of having fungal infections, the BDG test was more sensitive (detecting about 64% of true infections at a cutoff of 60 pg/mL), while the GM test was more specific (correctly ruling out infections about 93% of the time).¹³ These tests are designed for hospitalized, immunocompromised patients, not for outpatient screening of people with chronic fatigue or brain fog after living in a damp house.

Traditional fungal cultures and molecular techniques are also used for diagnosed infections. In chronic rhinosinusitis (chronic sinus inflammation), for example, high-sensitivity molecular methods have actually shown that fungi play a role only in a small subset of patients, and standard cultures tend to favor fast-growing organisms, potentially missing others.¹⁴

Allergic Bronchopulmonary Aspergillosis

One specific condition sits at the intersection of allergy and fungal colonization: allergic bronchopulmonary aspergillosis (ABPA). This occurs when Aspergillus fungus colonizes the airways and triggers an intense allergic and inflammatory response, almost always in people who already have asthma or cystic fibrosis. It is not common even among asthmatics, with studies finding rates around 3 to 5.5% depending on the diagnostic criteria used.¹⁵

Diagnosing ABPA requires a combination of findings. Updated international guidelines recommend that diagnosis starts with demonstrating sensitization to Aspergillus (through skin testing or specific IgE) and showing a total serum IgE level of 500 IU/mL or above, then confirming with at least two additional criteria from a set that includes Aspergillus-specific IgG, elevated blood eosinophils, or characteristic findings on lung imaging.¹⁶ No single test is enough on its own. If you have poorly controlled asthma and recurrent lung infiltrates, ABPA is worth investigating. It has a clear diagnostic pathway and effective treatment with antifungals and corticosteroids.

The CIRS Testing Framework

If you have done any reading about mold illness online, you have likely encountered the term Chronic Inflammatory Response Syndrome (CIRS), a framework popularized by a physician named Ritchie Shoemaker. The idea is that exposure to biotoxins, including mold-derived mycotoxins, triggers a chronic multi-system inflammatory response in genetically susceptible individuals. CIRS practitioners use a panel of tests that mainstream medicine views with varying degrees of acceptance.

Visual Contrast Sensitivity Testing

One screening tool commonly used in the CIRS framework is the visual contrast sensitivity (VCS) test, which measures your ability to distinguish between varying shades of gray in striped patterns. The theory is that biotoxin exposure impairs the neurological pathways involved in contrast perception. A recent study comparing multiple VCS testing methods found that contrast sensitivity was significantly reduced in biotoxin-exposed participants when measured with digital VCS tests, with one experimental digital test achieving 100% sensitivity and 60 to 80% specificity. However, the original Shoemaker handheld chart did not distinguish between exposed and unexposed groups.¹⁷ That last detail matters because the handheld chart is the version most patients encounter in practice.

HLA Genetic Typing

Another component of the CIRS workup is HLA-DR/DQ genetic testing. The hypothesis is that certain variations in these immune-system genes make some people poor eliminators of mycotoxins, turning even brief exposures into chronic problems. A case report series described four patients whose HLA-DR/DQ alleles were linked to what the authors called mycotoxin susceptibility due to a weaker immune clearance response.¹⁸ Another published case described a patient with an HLA-DR/DQ haplotype characterized as “multisusceptible,” alongside elevated inflammatory markers.¹⁹

The evidence base here is thin: case reports and small series, not controlled trials. HLA typing is a legitimate medical test used routinely for transplant matching and autoimmune disease diagnosis, but its use in predicting who will develop chronic illness from mold exposure has not been validated in large populations. A four-patient case series cannot establish that a particular genetic variant causes susceptibility to mycotoxins. Mainstream allergy and environmental medicine societies have not endorsed HLA typing for this purpose.

The Diagnostic Overlap Problem

One of the biggest challenges in “testing for mold” is that the symptoms attributed to mold illness are extremely nonspecific. Fatigue, brain fog, headaches, muscle pain, digestive issues, and mood changes overlap with dozens of other conditions. A study of patients with chronic fatigue syndrome who had mycotoxins detected in their urine documented an extraordinary range of prior diagnoses in the same patients, including fibromyalgia, Lyme disease, peripheral neuropathy, irritable bowel syndrome, anxiety, depression, chemical sensitivity, chronic sinusitis, and cognitive dysfunction.²⁰

This does not mean mold cannot contribute to these symptoms. It means that finding mycotoxins in someone’s urine and observing that they have fatigue does not establish that the mycotoxins caused the fatigue, especially when (as discussed earlier) nearly everyone has detectable mycotoxin levels from food. A clinician who skips the differential diagnosis and attributes a patient’s symptoms to mold based on a urine panel may miss a treatable condition.

What a Reasonable Testing Approach Looks Like

If you suspect mold is affecting your health, the most productive steps depend on your specific symptoms. For respiratory or allergic symptoms that worsen in certain environments, standard allergy testing with skin prick tests or specific IgE to common mold species is well-validated and available through any allergist. If those come back positive and your symptoms correlate with indoor mold exposure, you have an answer and a treatment pathway (mold remediation plus standard allergy management).

For persistent, poorly controlled asthma with abnormal chest imaging, ask your pulmonologist about ABPA workup, which follows a defined diagnostic algorithm. For immunocompromised patients with fever and suspected infection, galactomannan and BDG testing belong in the hospital setting, ordered by infectious disease specialists.

For the murkier category of chronic multi-system symptoms in someone living or working in a visibly water-damaged building, the most evidence-supported first step is not body testing at all. It is environmental assessment and remediation. Getting out of, or thoroughly cleaning up, the moldy environment is the intervention most consistently associated with symptom improvement. The German clinical guidance reflects this priority, emphasizing that environmental evaluation and remediation come first, with body testing generally not indicated.²

Sauna Protocols and Detox Claims

Alongside testing, many practitioners in the mold illness space recommend detoxification protocols: binding agents like cholestyramine or activated charcoal, saunas, IV antioxidants, and various supplements. One published case series described a protocol combining environmental cleanup, antigen injections, oral and intravenous antioxidants, sauna therapy, and oxygen therapy. Of 28 patients treated, 27 reportedly improved and returned to work.²¹

A 28-person uncontrolled case series with no comparison group cannot tell you whether the treatment worked, or whether the patients improved because they also moved out of their moldy environments, because time passed, or because of a placebo effect. The multi-component protocol makes it impossible to attribute improvement to any single element. These treatments are not harmful in most cases (sauna use is generally safe for healthy adults), but framing them as validated mold detoxification oversells the evidence. If a practitioner orders a urine mycotoxin panel, then prescribes a detox protocol, then re-tests to show your levels dropped, keep in mind that your levels would likely fluctuate regardless, especially if you changed your diet or environment in the meantime.

Mold Sensitization Rates in the General Population

It helps to put the overall picture in perspective. Across European studies, allergic sensitization to molds affects roughly 3 to 10% of the general population.¹ Among asthmatics, rates are higher. Among people living in severely water-damaged buildings, rates are higher still. But even in those populations, mold sensitization is not universal, and sensitization alone does not automatically mean the mold is the primary driver of symptoms. The most useful testing paths are the ones that align a specific clinical question (allergy? infection? ABPA?) with a test designed to answer it, rather than casting a wide net with unvalidated panels and interpreting the results through a framework that has not been confirmed by large-scale evidence.

1
SpringerLink / Allergo Journal International. Abridged version of the AWMF guideline for the medical clinical diagnostics of indoor mould exposure
2
PubMed Central. Indoor Mold—Important Considerations for Medical Advice to Patients
3
Europe PMC / CDC. Notes from the field: Use of unvalidated urine mycotoxin tests for the clinical diagnosis of illness–United States, 2014
4
PubMed Central. Urinary deoxynivalenol is correlated with cereal intake in individuals from the United kingdom
5
PubMed Central. Mycotoxins in blood and urine of Swedish adolescents-possible associations to food intake and other background characteristics
6
PubMed Central. Mycotoxin Analysis of Human Urine by LC-MS/MS: A Comparative Extraction Study
7
PubMed. Kinetic parameters and intraindividual fluctuations of ochratoxin A plasma levels in humans
8
PubMed. How to diagnose mould allergy? Comparison of skin prick tests with specific IgE results
9
PubMed. Sensitization to fungi: epidemiology, comparative skin tests, and IgE reactivity of fungal extracts
10
PubMed Central. What should be tested in patients with suspected mold exposure? Usefulness of serological markers for the diagnosis
11
PubMed. Serum IgG and IgE antibodies against mold-derived antigens in patients with symptoms of hypersensitivity
12
Annals of Allergy, Asthma & Immunology. Immunoassays in toxic evaluation of environmental fungal exposure and health effects
13
PubMed Central. Assessment of the 1,3-beta-D-glucan test and the galactomannan antigen test in the detection of invasive fungal infections in patients with hematological diseases
14
PubMed Central. The microbiome of chronic rhinosinusitis: culture, molecular diagnostics and biofilm detection
15
PubMed Central. Diagnosis of Allergic Bronchopulmonary Aspergillosis in patients with persistent allergic asthma using three different diagnostic algorithms
16
PubMed. Revised ISHAM-ABPA working group clinical practice guidelines for diagnosing, classifying and treating allergic bronchopulmonary aspergillosis/mycoses
17
PubMed Central. Assessment of visual contrast sensitivity in biotoxin-exposed individuals using four testing methods I
18
PubMed. HLA gene variations and mycotoxin toxicity: Four case reports
19
PubMed Central. Reversal of Refractory Ulcerative Colitis and Severe Chronic Fatigue Syndrome Symptoms Arising from Immune Disturbance in an HLA-DR/DQ Genetically Susceptible Individual with Multiple Biotoxin Exposures
20
PubMed Central. Detection of Mycotoxins in Patients with Chronic Fatigue Syndrome
21
PubMed. The treatment of patients with mycotoxin-induced disease