What Does Mould Illness Look Like? A Nine-Month Case Study

This mould illness case study follows Sarah, 41, through nine months of recovery after three years in a water-damaged flat. Three urine mycotoxin tests tracked her progress. Her results rose before they fell, while her fatigue dropped from 8/10 to 2/10 and her ochratoxin A level fell by 96%.

Sarah’s name and some identifying details have been changed. This is one person’s experience. Recovery varies widely, and her results are not typical or guaranteed.

Key takeaways

• Leaving a water-damaged building is the essential first step, but many people still feel unwell for months afterwards. When leaving isn’t possible, limiting exposure is the next best option. This might look like limiting the time you spend in the most affected room(s).
• Sarah’s plan worked in phases: support the gut (bowels, bile and fibre) and cell membrane health, then add liver support and sauna once those were steady.
• Her four-month retest looked worse on paper. After ruling out new exposure and diet, we interpreted the rise as toxins being mobilised, though a urine test cannot prove this.
• By month nine, her ochratoxin A had fallen from 83.6 to 3.1 ng/g creatinine, and her fatigue, brain fog and bloating scores had dropped to 1–2/10.
• How you feel matters more than reaching zero on a urine mycotoxin test.

Who was Sarah, and what symptoms did she have?

Sarah is a 41-year-old project manager who spent three years in a rented flat with a slow leak behind the bathroom wall. When the landlord finally opened things up, there was visible mould behind the wardrobe and under the bath panel. Two months before our first appointment, she moved into a new home with no signs of damp or mould.

By the time we met, she was struggling with four clusters of symptoms, each self-rated from 0 to 10:

• Fatigue (8/10): waking unrefreshed and crashing by mid-afternoon. Weekends were spent recovering and preparing for another week.
• Brain fog (8/10): losing words mid-sentence and rereading emails several times.
• Gut symptoms (bloating 7/10): bloating most afternoons, loose stools alternating with constipation, and new reactions to foods she used to tolerate.
• Sinus symptoms: constant congestion and post-nasal drip, with two courses of antibiotics in the past year.

Her GP had already run a full blood count, ferritin, B12, thyroid, liver and kidney function, and a coeliac screen. All came back within range. Ruling out other causes first is always worth doing.

Sarah had expected to feel better once she moved. Leaving a water-damaged building or reducing exposure at the source is the essential first step, but it does not always clear what the body is already carrying, and for some, the immune system stays turned up driving chronic inflammation. Also some mycotoxins, such as ochratoxin A, bind tightly to proteins in the blood and recirculate between the liver and gut, which may help explain why symptoms can persist after the exposure ends (Kőszegi & Poór, 2016).

Why do some people recover from mould exposure faster than others?

Mould-related illness is a spectrum, not a single condition. Some people feel noticeably better within weeks of leaving a damp property. Others spend months, or even years, getting their health back.

In clinical practice, several factors seem to shape where someone lands on that spectrum:

• Amount of exposure: how much mould was present, how long they lived or worked there, and how much time they spent in the worst-affected rooms.
• Individual susceptibility: genetics (HLA-DR and HLA-DQ), existing health conditions and immune function.
• Overall load: stress, other toxic exposures, and how well the body’s detoxification and elimination pathways are working.

These are clinical observations rather than a validated scoring system. Exposure and susceptibility do, however, match the risk factors official guidance highlights for damp and mould (NHS).

At the more persistent end of the spectrum, some practitioners in functional and environmental medicine use the term CIRS, or chronic inflammatory response syndrome. It describes a pattern in which the immune system appears to stay switched on long after exposure ends, with fatigue, brain fog, pain and symptoms across several body systems. CIRS is not a mainstream diagnostic label.

Sarah sat somewhere in the middle. Three years of daily exposure was significant, and she was still clearly unwell two months after moving out. However, she did not show the wider multi-system pattern that would have led us to explore CIRS.

What did Sarah’s first mycotoxin test show?

Sarah’s baseline urine test showed raised ochratoxin A (OTA) at 83.6 ng/g creatinine and raised citrinin at 42.0 ng/g creatinine.

The test was a urinary mycotoxin panel on first-morning urine, corrected for creatinine. Before testing, Sarah followed a low-mould diet for two weeks. Our standard prep is around three days, but because her symptoms were long-standing, we chose a longer run-in to reduce dietary “noise” as far as possible. The diet cut back on foods that commonly carry mycotoxins, such as grains, nuts, dried fruit, coffee and wine (Charusalaipong et al., 2024; Kőszegi & Poór, 2016).

The pattern made sense. OTA and citrinin are both produced by Penicillium and Aspergillus species, which are common in damp buildings, and the two toxins are frequently found together (de Oliveira Filho et al., 2017). OTA binds tightly to albumin in the blood, which gives it a long half-life and helps explain why it lingers (Kőszegi & Poór, 2016).

Research has looked for these toxins in people like Sarah. In one study of 112 people with chronic fatigue syndrome, 93% had at least one mycotoxin in their urine, and OTA was the most common, found in 83% (Brewer et al., 2013). That study needs reading with care. Its comparison group was chosen to have no mould exposure at all, which can make an association look stronger than it is (Osterman, 2016). Earlier work from the same research group found mycotoxins in the urine, nasal secretions and tissue of people exposed to mould in their environment (Hooper et al., 2009).

You may like to check out our article exploring other signs you might be experiencing mould exposure.

What protocol did we use, and why in phases?

We worked in phases, guided by one rule: open the exit routes before increasing mobilisation. In clinical practice, people who release toxins faster than they can move them out often feel worse, so bowels, bile and fibre came first.

This was Sarah’s individual plan, built around her history and test results. It is not a template to follow without a practitioner.

Phase 1 (weeks 1–6): open the exit routes

• Low-mould diet: continued from her pre-test run-in, cutting back on nuts, dried fruit, aged cheeses, alcohol (especially wine and beer) and leftovers kept for days. This kept dietary mycotoxins low, so each retest would better reflect what was leaving her body rather than what was going in.
• Bitters before meals: used to encourage bile flow, a main route for moving many mycotoxins out via the gut. This is a clinical rationale; human evidence for bitters and mycotoxin clearance is limited.
• A phospholipid supplement: many mycotoxins are fat-soluble, which means they are drawn to fatty environments in the body. This matters because the membranes surrounding every cell are built largely from phospholipids, a type of fat. As a result, these compounds may be able to interact with, and pass into, cell membranes more readily than water-soluble substances. This interaction could have knock-on effects for your mitochondria, the structures that generate most of your cells’ energy. Mitochondria depend on healthy, intact membranes to hold an electrochemical gradient across them. That gradient is what drives the production of ATP, the molecule your cells use as fuel. If mycotoxins disrupt these membranes, energy production may be affected.
• The probiotic Lactobacillus rhamnosus GG: in laboratory studies, this strain bound aflatoxin B1 and reduced its passage through human gut cells (Gratz et al., 2007). Sarah had no aflatoxin at baseline, so we chose it as a gentle, food-grade strain for her gut symptoms, with toxin binding as a possible extra rather than the main reason.
• A xylitol nasal spray, daily: for her ongoing congestion. In a small pilot trial of 20 people with chronic rhinosinusitis, xylitol irrigation improved symptoms more than saline over 10 days (Weissman et al., 2011). Some practitioners also view the sinuses as a possible reservoir for ongoing exposure, but this is a hypothesis. Fungi are found in the noses of healthy people too (Ponikau et al., 1999).
• Dietary fibre: built up gradually towards the UK guideline of 30 g a day, and then beyond (NHS).

Before moving on, we wanted daily, comfortable bowel movements. Constipation means slower transit and more time for toxins to be reabsorbed.

We deliberately did not start with stronger binders. For Sarah, a fibre-first approach was gentler on a gut that was already reactive.

Can fibre help bind mycotoxins?

Soluble fibre may help to a modest degree, but the evidence is early. In a laboratory digestion model, adding fibres such as pectin to food reduced how much of several mycotoxins was available for absorption (López-Ruiz et al., 2023). The same authors note there is still little experimental evidence on dietary fibre as a mycotoxin binder.

The reason fibre matters is a loop called enterohepatic recirculation. Many mycotoxins are processed in the liver and sent into the gut with bile. OTA in particular can be reabsorbed from the intestine and returned to the liver, so the body is exposed to it again and again (Kőszegi & Poór, 2016).

Soluble fibres such as psyllium, oat beta-glucan and ground flaxseed form a gel in the gut that may help break that loop. Fibre also speeds up transit and feeds the gut microbes that help maintain a healthy gut lining. We see it as a gentle, food-based foundation, not a strong binder on its own.

Phase 2 (weeks 6–16): support the liver and the brain

• Liposomal glutathione: started low and built up. Glutathione is one of the main molecules the liver uses to make toxins such as aflatoxin safe for removal (Raney et al., 1992).
• Bioflavonoids and antihistamine nutrients: chosen for two reasons. Luteolin has been studied for calming brain inflammation and the immune cells (mast cells) linked to brain fog, though that research wasn’t about mould it was about other conditions (Theoharides et al., 2015). Lab studies also suggests flavonoids like these can compete with OTA for its binding site on albumin, a protein in the blood (Kőszegi & Poór, 2016).
• Sauna: introduced at week 8, once her bowels and energy were steadier. She started with 10–15 minutes of infrared sauna and built up to 25–30 minutes, three to four times a week. She showered straight afterwards and replaced fluids and electrolytes. Sauna is widely used in mould recovery, but direct evidence that it clears mycotoxins through sweat is very limited.

By month four, Sarah’s fatigue had dropped to 6/10, her brain fog to 5/10 and her bloating to 4/10. Her sinuses were clearer. She did notice a few heavier, “wiped out” days after longer saunas, which some practitioners describe as a detox or Herxheimer-type reaction.

Why did her mycotoxin levels rise at month four?

A rising mycotoxin result does not always mean someone is getting worse – it’s actually something I see quite often. Once we had ruled out new exposure and diet, our working interpretation of Sarah’s month-four rise was mobilisation: toxins the body had been holding onto were being released and cleared.

At her four-month retest, after 16 weeks on the protocol, OTA had fallen from 83.6 to 11.2 ng/g creatinine. Citrinin, however, had risen from 42.0 to 68.5 ng/g creatinine. Aflatoxin M1 had also appeared for the first time, at 1.9 ng/g creatinine.

Before deciding what this meant, we checked the obvious alternatives:

• New exposure? We reviewed her new home, office and car, plus items brought from the old flat such as soft furnishings. Nothing pointed to a new source.
• Diet? She had followed the low-mould diet closely since before her first test, which made a new dietary source less likely. We also checked her dairy intake, because aflatoxin M1 can be present in milk (Antunović et al., 2022).
• Symptoms? She was clearly improving, not deteriorating.

With those checks done, mobilisation was the likeliest explanation. Better bile flow, more glutathione and regular sweating may have been releasing stored toxins. Aflatoxin M1 is a metabolite the liver makes from aflatoxin B1, so its appearance may reflect stored toxin being processed (Antunović et al., 2022).

It is important to be honest about the limits here. A urine test shows what is leaving the body, not what is stored, so it cannot prove mobilisation. In clinical practice, falling symptoms alongside a temporary rise in results is a pattern we see fairly often, but it is a clinical interpretation, not a certainty.

We kept the protocol going, nudged fibre up slightly, and reduced sauna to three sessions a week for a few weeks while she felt tired.

What did her nine-month retest show?

At nine months, all three mycotoxins had fallen well below her earlier results. OTA was down to 3.1 ng/g creatinine, citrinin from a peak of 68.5 to 9.8, and aflatoxin M1 from 1.9 to 0.6. Each was still detectable, but the trend was clearly downward.

Sarah’s fatigue was 2/10, her brain fog 2/10 and her bloating 1/10. Her gut had settled, her sinuses were clear and she was back at the gym.

Do mycotoxin levels need to reach zero?

No. Mycotoxins are common in everyday food, so low, detectable levels are expected even in healthy people (Charusalaipong et al., 2024). There is also no validated “normal” range for urine mycotoxin tests, let alone a validated target of zero (Kawamoto & Page, 2015).

After three tests over nine months, Sarah chose not to retest, and that was a reasonable decision. The test was a tool to guide the work, not the goal itself. She felt well, which was the outcome we were working towards.

We agreed a maintenance plan:

• Keep fibre high.
• Follow a relaxed version of the low-mould diet.
• Use the sauna once or twice a week.
• Taper supplements over two months.

If symptoms return or there is a new exposure, retesting would be the next step.

How did Sarah’s results change over nine months?

Over nine months, Sarah’s OTA fell by 96% and her citrinin by 77%, while her fatigue, brain fog and bloating scores each fell by 75% or more. The table below sets out every result in one place. Mycotoxins are in ng/g creatinine; symptoms are self-rated from 0 to 10.

Marker	Month 0	Month 4	Month 9	Change
Ochratoxin A	83.6	11.2	3.1	−96%
Citrinin	42.0	68.5	9.8	−77%
Aflatoxin M1	Not detected	1.9	0.6	Appeared at month 4, then fell
Fatigue	8	6	2	−75%
Brain fog	8	5	2	−75%
Bloating	7	4	1	−86%

Timeline at a glance

When	What happened
Before month 0	Moved to a dry home; two-week low-mould diet before testing
Month 0	Baseline urine mycotoxin test
Weeks 1–6	Phase 1: diet, bitters, phosphatidylcholine, probiotic, xylitol nasal spray, fibre
Weeks 6–16	Phase 2: glutathione, quercetin and luteolin added
Week 8	Infrared sauna introduced
Month 4	Retest: OTA down, citrinin up, aflatoxin M1 appears
Month 9	Retest: all three toxins down; symptoms 1–2/10
After month 9	Maintenance plan; supplements tapered over two months

What does this case teach about mould illness recovery?

The biggest lesson from Sarah’s case is that leaving a mouldy building starts recovery but rarely finishes it. Four principles shaped her plan:

• Leaving the building is step one (when possible), not the finish line. The body may still need support to clear what it is carrying.
• When leaving isn’t possible, limiting exposure is the next best option. Limit time in rooms most effected, and even consider sealing off the room with duct-tape to reduce mould spores and fragments traveling through the house.
• Open the exit routes first. Bowels, bile and fibre come before stronger mobilisation.
• A rising result is not always bad news. Rule out new exposure and diet before calling it mobilisation.
• Treat the person, not the number. Symptoms and quality of life are the outcomes that count.

Could something else explain symptoms like Sarah’s?

Yes, and it is worth checking the common causes first. Gut symptoms such as bloating, wind and changeable bowel habits are often caused by conditions like IBS rather than mould. Fermentable carbohydrates (FODMAPs) in everyday foods can trigger the very same symptoms, so they are worth looking at alongside anything mould-related, not instead of it.

If a wider pattern sounds familiar, such as histamine reactions, brain fog, fatigue or feeling better away from a particular building, our guide to the 7 signs you could be experiencing mould exposure covers it in more depth. You may also find these 9 hidden places useful when checking your home for mould.

Where does testing fit in?

A urine mycotoxin test is most useful when, like Sarah, you have a plausible exposure and symptoms that fit. Healthpath’s own urine mycotoxin test is launching soon.

Because so much of Sarah’s recovery ran through her gut, understanding your gut health is a valuable first step.

• The Ultimate Gut Plan uses an advanced stool test to look at your microbiome balance, inflammation and digestion, paired with a personalised plan from a practitioner.
• The SIBO Test uses a breath test to check for small intestinal bacterial overgrowth, a common and treatable cause of bloating and changeable bowels.

Neither test detects mould. Both can give you and a practitioner a clearer picture of your gut, which helps shape how a mould recovery plan is sequenced, and both are useful even if mould turns out not to be the main driver.

When should you see your GP during mould recovery?

See your GP promptly if your symptoms get worse, if you develop new ones, or if you notice any of these red-flag symptoms:

• Unexplained weight loss
• Blood in your stool
• Difficulty swallowing
• A persistent change in bowel habit
• Unexplained iron-deficiency anaemia
• Shortness of breath or coughing up blood

These need proper medical assessment and should not be put down to mould without review.

A few other checks are sensible alongside any mould recovery plan:

• Kidney function: OTA and citrinin can both affect the kidneys, so it is worth having kidney function checked (Kőszegi & Poór, 2016; de Oliveira Filho et al., 2017).
• Sauna: speak to your GP first if you have a heart condition, low or high blood pressure, or are pregnant.
• Supplements: these can interact with medicines, so check with your doctor or pharmacist if you take any.

Frequently asked questions

How long does it take to recover from mould illness?

It varies widely. Some people feel better within weeks of leaving a damp building, while others take months or years. In this case study, symptoms fell from 8/10 to 2/10 over nine months with a phased, practitioner-led plan.

Why do I still feel unwell after leaving a mouldy home?

Leaving the building is the essential first step (or at the minimum reducing exposure) but it does not clear what the body is already carrying. Some toxins, such as ochratoxin A, bind to blood proteins and recirculate between the liver and gut, so they can linger (Kőszegi & Poór, 2016).

What if I can’t move out?

Moving isn’t possible for everyone. Reducing exposure at the source is still the priority: report damp and leaks to your landlord or local council, improve ventilation, manage condensation and tackle any ongoing leaks. Our guide to 9 hidden places you’re exposed to mould every day covers practical steps. A practitioner can also help you work out what’s realistic in your situation.

Why did my mycotoxin levels go up during treatment?

A rise does not always mean you are getting worse. Once new exposure and diet are ruled out, a practitioner may interpret it as stored toxins being mobilised. A urine test shows what is leaving the body, not what is stored, so this is a clinical interpretation rather than proof.

Do mycotoxin levels need to reach zero?

No. Mycotoxins are common in everyday food, so low detectable levels are expected (Charusalaipong et al., 2024). There is no validated target of zero, and how you feel matters more than the number (Kawamoto & Page, 2015).

Can fibre help remove mycotoxins?

Possibly, to a modest degree. In laboratory digestion models, some dietary fibres reduced how much of certain mycotoxins was available for absorption, but human evidence is still limited (López-Ruiz et al., 2023).

Should I change my diet before a mycotoxin test?

Yes. A short low-mould diet beforehand, typically around three days, reduces dietary mycotoxins so your result better reflects your environmental burden. Follow the specific prep instructions for the test you use.

This article is for information only. It is not intended to diagnose, treat, cure or prevent any disease. It describes one person’s experience, and individual results vary. Always consult a qualified healthcare professional about your own circumstances.

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