What I wish I knew before starting mould testing

Could hidden mould be the missing link in your chronic health symptoms?

When I look back at one of the most frustrating periods in my health journey, the signs were all there – I just didn’t know what to look for.

I was already living with chronic fatigue syndrome (CFS), so fatigue wasn’t new to me, but something changed. Not long after moving into a new flat, I noticed my symptoms intensifying. I developed a persistent cough that didn’t respond to treatment, my migraines became more frequent and severe, and my baseline energy plummeted even further. Gut issues flared up again, and I started reacting to foods and smells I’d previously tolerated. It felt like I’d lost the progress I’d made – and at the time, I didn’t suspect my environment could be playing such a significant role.

I didn’t get the apartment tested – mostly because I didn’t know that was even an option. But in hindsight, the signs of hidden mould exposure were all around me. And now, after years of learning about environmental illness, I encourage every client with unexplained or persistent symptoms to consider mould testing as part of their health investigation.

Misconceptions about mould exposure

1. Mould exposure isn’t always visible or musty

One of the biggest misconceptions is that mould is easy to spot or smell. In my case, there was no dramatic black patch on the wall. But mould doesn’t need to be visible to be harmful. It can lurk behind walls, under flooring, or in damp corners with poor ventilation. Some moulds release mycotoxins – tiny compounds that become airborne and can affect your immune, neurological, and respiratory systems even if you can’t see a thing.

2. Symptoms often don’t point clearly to mould

If you have an autoimmune condition or CFS, mould exposure can mimic or intensify your symptoms: migraines that worsen in frequency or intensity, fatigue that becomes harder to recover from, sinus or respiratory issues that don’t resolve, and gut symptoms that seem to flare without a clear trigger. For me, it was the persistent cough, relentless migraines, and increasing sensitivity to smells and foods that made me start questioning the role of my environment.

When and how to test for mould

Back then, I didn’t know that environmental testing existed, let alone how to access it. But now, I always recommend that clients with mystery symptoms consider both home and body testing for mould.

For the home, ERMI (Environmental Relative Mouldiness Index) or HERTSMI-2 testing can be done by analysing dust samples for the DNA of mould species. These are particularly useful if you’re still living in the environment and want to understand your level of exposure.

For the body, mycotoxin urine testing may indicate whether your system is currently excreting mould toxins. These tests aren’t perfect – results can be influenced by your detox capacity – but they’re one piece of the bigger picture, especially when combined with symptoms and exposure history.

Even though I didn’t test my flat, I now see how clearly my symptoms aligned with mould-related illness. And in many cases, my clients see dramatic shifts once exposure is reduced and detox support is in place.

What I’d do differently

Looking back, I wish I’d trusted my instincts sooner. If I could rewind the clock, I’d be far more thorough when renting, especially in older properties, asking direct questions about ventilation and any history of damp. I’d pay closer attention to subtle warning signs like condensation on windows, that faint musty smell after rain, or signs of patch repairs that might be masking deeper issues. I would have explored the option of environmental testing earlier instead of continuing to chase every symptom without considering my surroundings. And even if moving wasn’t immediately possible, I would have created a mould-reduction plan to minimise exposure and protect my health in the meantime.

Taking action without overwhelm

When mould is a hidden variable, it can feel like a cruel sabotage to all your other health efforts. You might be eating well, sleeping properly, and taking all the right supplements, but if your environment is triggering your immune system, healing will always feel like an uphill battle.

Even if testing confirms mould and moving isn’t an option straight away, there are meaningful steps you can take to reduce your exposure and support your body’s recovery:

1. Start with air quality

A high-quality HEPA air purifier can significantly reduce the number of airborne mould spores and mycotoxins circulating in your home, especially in rooms where you sleep or spend long periods of time. Place one in the bedroom as a priority. Choose a model that also includes activated carbon to help filter volatile organic compounds (VOCs), which often accompany mould.

2. Improve ventilation

Kitchens, bathrooms, and laundry areas are hotspots for moisture. If your space doesn’t have proper extractor fans, open windows regularly and consider using a dehumidifier to keep indoor humidity below 50%. Mould thrives in moist environments, so even small changes in airflow and humidity can help.

3. Adjust your cleaning routine

Frequent cleaning with microfibre cloths helps trap spores rather than spreading them. Avoid bleach – it doesn’t effectively kill mould on porous surfaces and can worsen respiratory symptoms. Instead, use mould-specific cleaners like EC3 spray, which contains natural antifungal ingredients and is safe to use on soft furnishings.

4. Support your detox pathways

If your body is reacting to mould, it’s likely under a higher toxic load. Binding agents like activated charcoal or bentonite clay (used under practitioner guidance) can help absorb mycotoxins in the gut. Combine this with antioxidant support, such as glutathione, NAC, and milk thistle, to help your liver and cells cope with the increased demand. Hydration, regular bowel movements, and gentle sweating (e.g. sauna or Epsom salt baths) can also aid elimination.

5. Rebuild your immune resilience

A mould-exposed body often operates in a state of chronic alert. Prioritise deep rest, nutrient-dense meals rich in zinc, vitamin A, C, and D, and nervous system regulation techniques like breathwork, vagus nerve stimulation, and time outdoors. The goal is to shift your system out of fight-or-flight mode and into a state where it can recover.

When I did eventually move out of the flat, I noticed a shift – not overnight, but a slow, steady lifting of that dense, wired-but-tired fog. It wasn’t the only factor in my recovery, but it was a major turning point.

If you're struggling with a persistent plateau or unexplained worsening of symptoms, don’t overlook the environment around you. Mould exposure isn’t rare and it doesn’t only affect people with visible water damage in their homes. It can be subtle, insidious, and entirely overlooked.

My advice? Trust your instincts. If something feels off in your space – if your body feels better when you're away from home, or worse after a rainy weekend indoors – start asking questions. You don’t need to tackle everything at once, but awareness is the first step. And for many, it’s a game-changer.