Can Mold Cause Headaches?

Can Mold Cause Headaches

A question I often get asked is, “Can mold cause headaches”? In this article, we take a deep dive into this subject.

It has been estimated that 10-50% of indoor environments in Europe have clinically meaningful levels of mold (Source) – this doesn’t surprise me, having worked with hundreds of clients over the last few years who have developed various health conditions from living in a water-damaged property. This statistic comes from the World Health Organisation – so we should take it seriously.

That means many people are being exposed to a *significant* amount of mold!

WHO helpfully shared these primary indicators of dampness and microbial/fungal growth (i.e., signs there could be mold growth in your home) (Source):

  • Condensation – this could be on walls or around windows
  • Smell – A moldy odor
  • Poorly maintained A.C systems (more relevant for North America)
  • Water damage – current or past (two common examples being a burst pipe causing a leak or a damp basement)
  • And finally, visible mold (a rather obvious one!)

But what does this all mean when it comes to our health? Do we need to be concerned about mold or not? Unfortunately, you will read different things on different websites.

Before we dive into the evidence around whether mold can cause headaches, let’s cover some basics that might help us understand why there is such contradictory information out there.

Mold, Mold Spores, Mycotoxins: The Terrible Trio

Molds are fungi, and fungi love warm, damp, humid conditions. This is why we need to be mindful of things like condensation. There are literally thousands of species of mold. It is thought that the most common indoor molds belong to the genera Penicillium and Aspergillus (Source).

Mold spores, on the other hand, are small molecules produced by mold that help mold reproduce. They are found basically everywhere –  in soil, in our homes, and also in decaying vegetation.

Dr. Crista, world renowned expert in mold describes mold spores in her book Break The Mold as Supermans pod:

Spores are just like Superman’s pod. They’re equipped with a bit of food, survival intel, and a mode of delivery to find a new place to land and grow.”

Then, finally, we have mycotoxins. These are secondary metabolites of certain species of mold. They don’t smell. They are so tiny they enter our circulatory system from the lungs, where they can be transported into our organs and cells.

Do Molds Cause Disease?

Molds are known to induce various health conditions ranging from respiratory issues, such as respiratory infections or asthma, to allergies. They can be life-threatening in immunocompromised patients.

The ability of mold inhalation to cause respiratory problems is well-documented and widely accepted (Source).

But molds don’t just cause the above conditions. Their metabolites, mycotoxins, have been associated with a long list of symptoms, including chronic fatigue syndrome, multiple sclerosis, autism, irritable bowel syndrome….and many others.

Mold And Sick Building Syndrome

Mold, or mycotoxins, may be involved in “sick building syndrome.”, perhaps the best-known cause of CIRS – chronic inflammatory response syndrome. This is where patients with environmental mold exposure present with atypical constitutional and systemic symptoms, associating those symptoms with the contaminated environment. Another term used interchangeably with sick building syndrome is “Toxic mold syndrome.”

One symptom frequently reported by those suffering with sick building syndrome is headaches (see the studies evidencing this below).

Headaches are a known symptom of toxic mold exposure” – Real Time Labs

While not evidence, the fact that the worlds leading clinicians and researchers in this area, including Dr. Jill Crista, Dr. Neil Nathan, and Dr. Richie Shoemaker all list migraines or/and headaches as symptoms of mold exposure, I feel, is important to mention too.

The Evidence:

There are numerous papers published in peer reviews scientific journals showing us headaches are a common cause of mold exposure. Here are six to hammer the point home:


1. The authors in one paper studied associations between two mycotoxins (sterigmatocystin and verrucarol) in schools and rhinitis and other weekly sick building syndrome symptoms in the students. (Source) Several symptoms were experienced on a weekly basis: nasal symptoms (rhinitis) (18.8%), ocular (11.6%), throat (11.1%), dermal symptoms, headache (20.6%) and tiredness (22.1%) were common. (Source)


2. Another paper presented an overview of the neurological significance of abnormal natural killer cell activity (a type of immune cell) in chronic toxic mold exposure. The authors concluded that “In the light of this review, it is concluded that chronic exposures to toxigenic mold could lead to abnormal natural killer cell activity with a wide range of neurological consequences, some of which were headache.” (Source)


3. In another study the researchers were actually primarily investigating how best to test toxic indoor air. However the researchers were also looking at pupils from a water-damaged school and the symptoms they were experiencing due to being exposed to toxic indoor air. The health of the pupils from water-damaged and healthy schools were interviewed using a questionnaire. Headache was one of the many symptoms that came back statistically significant (Source).


4. In another study, in a total of 65 individuals, 34% of them were experiencing headaches.  Other symptoms the group were experiencing included a cough (52% occurrence), respiratory symptoms (34% occurrence), and 23% were suffering from fatigue) (Source).


5. Another group of researchers studied dampness and mold in China and correlated the exposure to symptoms such as headache and fatigue. They concluded dampness and mold are common in Chinese homes and are associated with rhinitis and ocular, throat, and dermal symptoms, headache, and fatigue (Source).


6. The inflammatory sinus changes with chronic fungal sinusitis can contribute to referred unusual facial pain. Parts of the trigeminal nerve become irritated or permanently damaged, and this leads to unusual pain. Especially in patients with a predisposition toward migraine, but even in patients with no prior history of headaches, we can frequently see common migraines (without aura or complicated features usually) develop. The better the inflammatory process is managed in the sinuses, the more easily the migraines are managed (Source).

How Does Mold Cause Headaches?

Molds are responsible for diseases in humans through the three pathogenetic mechanisms:  infection, allergy, and toxicity (Source).

Infection: this is a risk factor for immunocompromised individuals, but it can occur in immunocompetent people as well.

Allergy: this might manifest as asthma, for example.

Mycotoxicosis: some will say this is almost exclusively the result of ingestion of mould-contaminated foodstuffs. I, and many others, would argue that exposure to a water-damaged moldy property is the most common cause.

Perhaps the second mechanism is most relevant when considering does mold cause headaches. Some argue that the main mechanism behind mold exposure causing headaches is that mold spores can irritate the respiratory system (such as the lungs) and the immune system, both of which may cause sinus issues. Sinus issues can cause headaches/migraines.

There is perhaps another mechanism, though. When mast cells are activated by fungi, they provoke an increase of a substance called PGD2 that may lead to hypersensitivity diseases which may manifest as irritation of the respiratory tract and eyes, recurrent sinusitis, bronchitis, cough, and neurological manifestations including fatigue, nausea, headaches and brain fog (Source).

Why Is This Information Not Widely Known?!

Mr. Epting summed this up best in his paper entitled ‘Neurologic and neuropsychiatric syndrome features of mold and mycotoxin exposure’ (Source):

“For several reasons, the neurologic and neuropsychiatric effects of mold and mycotoxins in humans have been less well-studied and, in some circles, controversial. First of all, the nervous system is extremely complex, and there is a wide range of individual variations in how the central nervous system, the peripheral nervous system, and the autonomic nervous system react to biologically toxic molecules”.

“Secondly, there is a wide range of biotoxins molds produce and many combinations of molds that can grow within a water-damaged structure. Hence, with a huge individual and organism diversity, almost an endless number of combinations of exposure-reaction profiles will occur. And lastly, in recent decades, most of the attention brought to focus upon humans with exposure to water-damaged buildings has been in the legal arena. In this naturally adversarial legal milieu, scientific methods can be obfuscated, and often, all parties can become discredited and/or dismissed. The process can then lead to individuals and resources abandoning the area of study.” (Source)

Final Consideration

As a final point, it is important to appreciate that mold spores are present in all indoor environments. So, the aim is never to try and eradicate them. As mentioned at the beginning, mold loves moist, humid environments, so one of the focuses needs to be on maintaining a low humidity in the property. I recommend buying a hygrometer to monitor humidity – we were so surprised to find that in the kitchen, humidity can get to 75% when cooking, for example. It is recommended to keep humidity below 50% to reduce the risk of mold growth.

So when we see mold indoors there has to be an inappropriate supply of water. This simply must be corrected before starting any remediation of the property.

Check out my interviews with Andy from Action Dry to learn more about property inspection and remediation and, with Dr. Jill Crista to learn more about the health consequences of mold and mycotoxins and things to consider when in poor health.


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