What Are The Symptoms of Mould Illness?

Understanding Mould Illness: Two Types of Reactions

Key takeaway:

Symptoms of mould exposure fall into two categories – allergy reactions to mould spores and mycotoxin illness. Search online and most of the information you find will tell you about mould allergy symptoms, but that’s not the full story.

Allergy vs Toxicity

Search online and most of the information you find will tell you about mould allergy symptoms, but that’s not the full story.

Some experience immediate allergy symptoms triggered by inhaling mould spores, while others develop mycotoxin-related illness, which is an accumulation of mycotoxins inside the body that can linger for years, even after exposure ends. A person may have one or both of these conditions.

• Allergy symptoms occur when your immune system reacts to spores in the environment.
• Mycotoxin illness (mould toxicity) happens when mould toxins accumulate inside the body.

On our website, we use “mould illness” as an umbrella term for all symptoms arising from mould exposure. The important thing to know here is simply that there’s much more to the picture than mould allergy and if you’ve been exposed to mould, it may be worth looking deeper.

Allergy Symptoms: Immediate Reactions to Mould Spores

Key takeaway:

Allergy symptoms are related to exposure to mould spores and are mainly respiratory.

Symptoms of mould allergy can include:

• Sneezing, runny nose, or stuffy nose
• Itchy or watery eyes
• Skin rashes
• Coughing, wheezing, or shortness of breath
• Sore throat

These symptoms typically flare when in a mouldy environment and often improve once the exposure is removed (although the picture may be more complicated if the mould has colonised the body).

Mycotoxin Illness: Long-Term Effects of Mould Toxins

Key takeaway:

Mould toxicity can linger for years, even long after exposure, and affect many aspects of health.

Mould Toxicity Symptoms

Unlike allergy symptoms, mycotoxin illness develops from mould toxins that accumulate inside the body. Mycotoxins are exceptionally small — far smaller than mould spores — and travel easily through the body, interfering with multiple systems simultaneously. This is why symptoms vary so greatly from person to person. Research suggests that genetic factors influence how well the body can clear mycotoxins, which is why one person in a mouldy home may become severely ill while others in the same household are unaffected.¹

The list that follows is not exhaustive – if you have concerns, take our Mould Illness Questionnaire.

Most Common Mould Illness Symptoms

The following symptoms are common with mould illness²:

• Headaches
• Poor sleep
• Fatigue
• Brain fog
• Mood changes
• Skin issues
• Sinus issues
• Digestive issues
• Symptoms & Conditions Highly Related to Mould Illness
• “Ice pick” or “lightning bolt” sensations
• Frequent static shocks
• Internal tremor or vibration
• Fibromyalgia, ME, or Chronic Fatigue Syndrome

If you recognise one or more of these, it may be worth investigating further with our Mould Illness Questionnaire.

Symptoms & Conditions Highly Related to Mould Illness

According to Dr Neil Nathan MD, a medical doctor who specialises in mould illness, and MastCell360, a group of naturopathic practitioners who specialise in mould illness, the following symptoms are classic mould giveaways:

• “Ice pick” or “lightning bolt” sensations
• Frequent static shocks
• Internal tremor or vibration
• Fibromyalgia, ME, or Chronic Fatigue Syndrome³

If you notice one or more of these, it may be worth investigating further with our Mould Illness Questionnaire.

Additional Symptoms of Mould Illness

Key takeaway: Mould can affect almost any system in the body, causing a wide range of symptoms.

1. Respiratory Issues

• Chronic sinus problems or infections
• Persistent coughing, wheezing, chest tightness, shortness of breath^{1, 4, 5}

2. Chronic Fatigue & Body Aches

• Debilitating tiredness
• Muscle aches, joint pain, cramps¹

3. Cognitive & Neurological Disturbance

• Poor memory or concentration
• Dizziness or balance problems
• Tingling or numbness¹

4. Mood & Mental Health

• Anxiety, depression, or irritability
• Mood swings¹

5. Digestive Distress & Food Sensitivities

• Nausea, abdominal pain, diarrhea
• Malabsorption or unusual food sensitivities¹

6. Skin & Sensory Reactions

• Rashes, eczema-like patches, redness, itchiness
• Sensitivity to light, sound, chemicals, and EMFs¹

7. Other Clues

• Night sweats
• Metallic taste in the mouth
• Frequent urination
• Temperature regulation issues¹

If you recognise clusters of symptoms, or any of the highly related symptoms above, taking our Mould Illness Questionnaire can help clarify whether mould may be contributing to your health issues.

For those whose questionnaire results suggest a higher likelihood of mould illness, a urinary mycotoxin test can provide more definitive insights. You can learn more about it here.

Why Mould Illness Is So Often Missed

If you have taken a mould allergy blood test (the kind offered by your GP) and got a negative result back, you may still have mould illness. This is one of the most common sources of confusion for people with mould illness, and it is worth explaining clearly.

Standard allergy blood tests measure IgE antibodies – an immune response associated with classic allergies.  They are designed to detect sensitivity to mould spores in the environment.  They are not designed to detect mycotoxin accumulation in the body, and a normal result does not rule out mould illness.

The testing approach used by mould illness specialists look at different markers entirely. Urinary mycotoxin testing is the choice of experts and can identify specific mycotoxins present in the body, providing a clearer picture of whether toxic mould exposure is contributing to your symptoms. You can read more about testing for mould illness here.

This gap between standard medical testing and specialist testing is one of the main reasons people with mould illness spend years – sometimes decades – without a diagnosis.

Taking the Next Step

Key takeaway:

Experiencing symptoms of mould illness can be concerning, but support is available.

Get Support Here

It’s completely understandable to feel worried if you’re experiencing any of the symptoms above. Mould illness is complex, but there are practical steps you can take to identify exposure, support your body, and begin recovery.

If you want to learn more, you can download our free ebook Is Mould Making You Unwell?, or contact us directly and we’ll help you get the help you need.

1. Valtonen V. Clinical Diagnosis of the Dampness and Mold Hypersensitivity Syndrome: Review of the Literature and Suggested Diagnostic Criteria. Front Immunol. 2017 Aug 10;8:951. doi: 10.3389/fimmu.2017.00951. PMID: 28848553
2. Hope J. A review of the mechanism of injury and treatment approaches for illness resulting from exposure to water-damaged buildings, mold, and mycotoxins. Scientific World Journal. 2013 Apr 18;2013:767482. doi: 10.1155/2013/767482. PMID: 23710148
3. Brewer JH, Thrasher JD, Straus DC, Madison RA, Hooper DC. Detection of Mycotoxins in Patients with Chronic Fatigue Syndrome. Toxins. 2013;5(4):605‑617. PMID: 23580077
4. Lee RJ, Workman AD, Carey RM, Chen B, Rosen PL, Doghramji L, Adappa ND, Palmer JN, Kennedy DW, Cohen NA. Fungal Aflatoxins Reduce Respiratory Mucosal Ciliary Function. Sci Rep. 2016 Sep 14;6:33221. doi: 10.1038/srep33221. PMID: 27623953
5. Øya E, Becher R, Ekeren L, Afanou AKJ, Øvrevik J, Holme JA. Pro-Inflammatory Responses in Human Bronchial Epithelial Cells Induced by Spores and Hyphal Fragments of Common Damp Indoor Molds. Int J Environ Res Public Health. 2019 Mar 26;16(6):1085. doi: 10.3390/ijerph16061085. PMID: 30917597