12 Signs Your House Has Toxic Mould & What To Do About It
You can’t always see it. You might not smell it.
But if you or your family have been feeling unwell — and nothing else explains it — hidden mould might be the reason.
Mould-related illness is more common than most people realise, and it’s often misdiagnosed as stress, burnout, anxiety, or even just parenting exhaustion.
This blog walks you through 12 subtle (and not-so-subtle) signs that your home may be harbouring mould — plus what to do next, especially if you’re renting.
1. You Can’t Shake Certain Symptoms
The number one red flag? Persistent symptoms that don’t respond to treatments — especially if more than one family member is affected.
Common mould-related symptoms include:
Fatigue or low energy
Brain fog or trouble concentrating
Headaches or migraines
Rashes, hives or eczema
Itchy eyes, sinuses, or throat
Mood changes, anxiety or sleep issues
Asthma, wheezing or frequent coughing
Feeling worse at home but better when away
If you’ve ever said, “I just don’t feel right in this house,” listen to that.
2. Your Child’s Behaviour Suddenly Changed
Mould can affect the brain — and in children, this often looks like:
Hyperactivity or sensory overload
Emotional outbursts or increased tantrums
Speech delays or regression
Difficulty concentrating or sitting still
Waking frequently during the night
Skin issues that don’t resolve with creams or elimination diets
If your child has suddenly become “a different kid,” especially after moving house, trust your gut.
3. The House Smells Musty or Earthy (Even After Cleaning)
A damp, earthy smell — even without visible mould — is a key clue. This often means mould is growing behind walls, under flooring, or in the ceiling cavity.
4. You’ve Had Leaks, Floods, or Storm Damage (Past or Present)
Even if a leak was “fixed,” water-damaged building materials can grow mould within 24–48 hours if not properly dried.
Look for:
Stains or bubbling on ceilings or walls
Peeling paint
A history of burst pipes, flooding, or roof leaks
5. Your House Plants Are Dying or Mouldy
Over-watered or rotting plants can encourage mould growth — and dying plants may indicate poor indoor air quality. Check the soil and leaves for fuzzy growth or black spots.
6. Your Air Purifier Is Showing Alarming Numbers
If you use an air purifier with a particle or VOC sensor, you might see unexplained spikes in levels — especially in certain rooms. That’s often a clue your home has poor air quality, possibly from mould spores or hidden mycotoxins.
7. There’s Visible Mould (Even If It’s Just a Little)
Small patches of mould — under windows, in bathrooms, inside wardrobes — are often dismissed as cosmetic. But they could be the tip of a much bigger issue behind the walls.
8. You Feel Better When You Leave the House
One of the strongest signs of mould illness is “location-based symptoms.”
If you feel clearer, calmer, or healthier on holidays, at work, or outdoors — but symptoms return when you’re home — mould might be playing a role.
9. There’s Excess Condensation or Dampness
Condensation on windows, damp corners in the wardrobe, musty cupboards — these are signs your house may not be breathing properly, creating the perfect environment for mould to grow.
10. You Get Static Shocks or Electrical Sensitivity
Dr. Shoemaker’s research on mould illness includes increased sensitivity to static electricity and devices. Some people feel more “charged,” experience more static shocks, or feel odd sensations when touching electronics in mouldy homes.
11. Your Pets or Plants Are Unwell, Too
Mould doesn’t just affect humans. If your pets have developed skin, breathing, or behavioural issues — and your vet can’t explain why — your environment may be the culprit.
12. You Just Know Something Is Wrong
You’ve cleaned the food. You’ve changed the products. You’ve done the “right” things… and nothing has worked.
You don’t need a visible patch of black mould to be affected. You just need exposure to water-damaged building materials — and a body that struggles to detox the toxins released.
What to Do Next (Especially If You’re Renting)
1. Start by tracking your symptoms.
We’ve created a full symptom checklist based on Dr. Shoemaker’s work.
→ [Download the Symptom Checklist Here] (Add this once formatted)
2. Consider Mould or Mycotoxin Testing
You can test for mould exposure and biotoxin load with an at-home test like the:
→ [i-screen Mould & Mycotoxin Test (Affiliate Link)]
This simple urine test helps detect key toxins produced by mould, including ochratoxin A, gliotoxin and others. It’s one of the first tools we recommend if symptoms are pointing toward hidden exposure.
3. If You’re in a Rental…
In Australia and New Zealand, landlords are legally responsible for providing a safe, habitable home. If you’ve found mould:
Document it with photos
Report it in writing (email or maintenance app)
Request immediate remediation — not just surface cleaning
If ignored, consider escalation through your local tenancy authority (e.g. VCAT in Victoria)
We’ll be releasing a free rental mould letter template soon to help you advocate for your rights.
Final Thought
Mould can be overwhelming. But knowing what to look for is the first step toward recovery.
You don’t need to panic — and you don’t need to spend thousands to start learning what’s going on. You just need to be informed.
→ Ready to learn more?
Start with our free 5-day email course: “Is It Mould? Learn the Signs + What to Do Next”