Chronic Inflammatory Response Syndrome

What is CIRS?

Chronic Inflammatory Response Syndrome (CIRS) is a term used by some clinicians to describe a pattern of persistent symptoms and inflammatory changes believed to occur in susceptible individuals following certain environmental exposures, particularly exposure to water-damaged buildings.

The CIRS model proposes that exposure to mold, microbial fragments, and other substances found in some water-damaged environments may trigger an ongoing inflammatory response in certain individuals. Some CIRS protocols also consider genetic susceptibility, immune and inflammatory markers, environmental testing, and other clinical findings as part of the evaluation.

CIRS remains an evolving and debated area of medicine. Although health effects from damp and moldy indoor environments are well established, the specific diagnostic criteria, biomarkers, and mechanisms proposed for CIRS are not universally accepted within conventional medicine.

At Functional Medicine Collaborative, we consider a patient's symptoms, medical history, environmental exposures, previous testing, and other possible causes as part of a broader evaluation rather than relying on any single test or marker to determine whether CIRS is responsible for their symptoms.

What Is CIRS?

CIRS is a multisystem, multi-symptom illness caused by chronic exposure to biotoxins. A biotoxin is a toxic substance produced by a living organism—such as bacteria, mold, algae, or fungi—that can trigger harmful effects in the human body. Unlike synthetic toxins (like pesticides or heavy metals), biotoxins are naturally occurring but can still cause serious health issues in susceptible individuals.

For some people biotoxins are not cleared effectively by the immune system which leads to an out-of-control immune response. The result? Chronic inflammation that doesn’t go away—even long after the original exposure.

Common Symptoms Associated With CIRS

People evaluated for CIRS often report symptoms affecting multiple areas of the body. These symptoms can vary considerably and may include:

• Persistent fatigue

• Difficulty concentrating or “brain fog”

• Headaches

• Muscle or joint discomfort

• Numbness or tingling

• Sleep disturbances

• Sinus or respiratory symptoms

• Digestive concerns

• Mood changes

• Increased sensitivity to certain environments

These symptoms are not specific to CIRS and can occur with many other medical conditions. Experiencing several of them does not necessarily mean that a person has CIRS, which is why a broader medical evaluation and consideration of other possible causes are important.

Our Approach

Our approach begins with a comprehensive evaluation of your symptoms, health history, environmental exposure history, previous testing, and treatments you may have already tried. Because CIRS symptoms can overlap with many other conditions, our practitioners consider the broader clinical picture when determining what evaluation and care may be appropriate.

Environmental Exposure Assessment

When exposure to a water-damaged or moldy environment is suspected, we discuss your exposure history and steps that may be appropriate to reduce ongoing exposure. Addressing moisture problems and properly remediating indoor mold is an important part of reducing continued exposure.

Individualized Laboratory Testing

Depending on your symptoms, health history, and previous evaluation, your practitioner may recommend laboratory testing. This may include inflammatory or hormonal markers, HLA genetic testing, Visual Contrast Sensitivity (VCS) screening, mycotoxin testing, or testing for other health conditions when clinically appropriate.

Functional Medicine Collaborative also has access to mycotoxin testing through Mosaic Diagnostics, Vibrant Wellness, and MyMyco.

These tests are interpreted alongside the patient's symptoms, history, exposures, and other clinical findings. Some tests used within CIRS-focused care, including VCS, HLA testing, and mycotoxin testing, have limitations and are not universally accepted as diagnostic tests for CIRS or illness caused by indoor mold exposure.

Individualized Treatment & Support

Treatment recommendations are individualized based on the patient's symptoms, health history, evaluation, and test results when applicable. Depending on the individual, recommendations may include nutrition and lifestyle changes, supplements, medications prescribed by an appropriately licensed practitioner, and other supportive therapies.

Some CIRS-focused treatment approaches use medications such as cholestyramine or other binding agents. When these therapies are considered, your practitioner can discuss their intended use, potential benefits, limitations, and possible side effects as part of your treatment plan.

Ongoing Follow-Up

CIRS and other complex health concerns may require ongoing evaluation and follow-up. Your practitioner will review your progress, changes in symptoms or environmental exposures, laboratory findings when applicable, and your response to treatment so that recommendations can be adjusted over time.

Common Questions About CIRS

What does CIRS stand for?

CIRS stands for Chronic Inflammatory Response Syndrome. The term is used by some clinicians to describe a proposed multisystem illness associated with an ongoing inflammatory response following certain environmental exposures, particularly exposure to water-damaged buildings.

Is CIRS the same as mold illness?

Not exactly. Mold and water-damaged buildings are commonly discussed in connection with CIRS, but the CIRS model can include exposure to other environmental substances as well. Mold exposure can also cause established health effects, such as allergic and respiratory symptoms, without a person having CIRS.

How is CIRS diagnosed?

There is currently no single universally accepted test for diagnosing CIRS. Practitioners who evaluate patients for CIRS may consider symptoms, environmental exposure history, laboratory findings, and other clinical information. Some CIRS-focused approaches also use testing such as VCS screening, HLA genetic testing, inflammatory markers, and mycotoxin testing.

These methods have limitations, and some are not widely accepted as validated diagnostic tests for illness related to indoor mold exposure. Results should therefore be considered as part of a broader clinical evaluation rather than used alone to make a diagnosis.

Is CIRS recognized by conventional medicine?

CIRS remains an evolving and debated area of medicine and is not currently widely accepted as an established diagnosis within conventional medicine. Research supporting CIRS diagnostic and treatment frameworks has been published, but questions remain regarding diagnostic criteria, biomarkers, and treatment approaches.

At Functional Medicine Collaborative, we discuss these limitations with patients and consider CIRS-related findings within the broader context of their health history, symptoms, environmental exposures, and other possible causes.

Can CIRS be treated?

Treatment approaches used for patients with suspected or diagnosed CIRS vary depending on the practitioner and the individual patient. Care may involve reducing ongoing environmental exposure, addressing identified health concerns, nutrition and lifestyle support, supplements, medications when appropriate, and ongoing monitoring.

Some practitioners use structured CIRS treatment protocols, including binding agents such as cholestyramine. Evidence supporting these protocols is still developing, and treatment should be individualized based on the patient's health history, evaluation, and needs.