If You’re Always Sick, the Hidden Culprit Behind Your Mystery Symptoms Might Be Growing on Your Walls

You know the drill: endless Google rabbit-holes, a nightstand full of half-finished supplements, and that nagging feeling that something just isn’t right. If you’re chasing unexplained fatigue, brain fog, weight changes, or mood swings, you may have a mystery illness on your hands. And what if the culprit isn’t inside your body—but inside your house?

Dr. Jess Peatross learned this the hard way. Despite being a physician who should theoretically have all the answers, she found herself gaining 30 pounds over three years, waking up in tears, and struggling with emotional regulation that felt completely foreign to her. “It was upsetting when you’re a doctor and you should have the answer,” she tells Dr. Will Cole on The Art of Being Well.

Her mystery illness? Mold exposure.

Why symptoms often hide behind mold

Mold toxins (aka mycotoxins) are particularly insidious because they can mimic dozens of other conditions. According to the Center for Disease Control and Prevention (CDC), the compounds can trigger weight fluctuations, hormonal chaos, and next-level mood swings while leaving standard labs squeaky-clean. In other words, mold is the ultimate catfish—it looks innocent, but wreaks havoc behind the scenes.

The frustrating part? Mold doesn’t need dramatic circumstances to take hold. Forget the flooded basement scenario—a slow drip under your kitchen sink or a neglected HVAC filter can create the perfect breeding ground. Modern homes, built to be energy-efficient and airtight, can trap moisture and create what amounts to a terrarium for toxic fungi.

Mold exposure symptoms worth paying attention to

See a doctor immediately if you have the following symptoms:

Allergies that ignore the calendar. If you’re sniffly and congested year-round, especially when you’re indoors, environmental factors might be at play.

Skin that’s constantly angry. New rashes, unexplained hives, or persistent skin irritation that doesn’t respond to typical treatments can signal mycotoxin exposure.

Energy that disappears without warning. Not just tired—but that bone-deep exhaustion that makes thinking through simple tasks feel monumental.

Cognitive symptoms that feel neurological. When “brain fog” starts interfering with work or relationships, and you find yourself struggling with concentration in ways that feel genuinely concerning.

If more than one box is checked, pull on your detective trench coat. As Dr. Cole reminds listeners, the journey starts with curiosity. “Please be open-minded because until you experience something like this personally in your life, it’s really good to be objective,” he states.

How to heal from mold-driven mystery illness

• Test your space—not just yourself. Professional air or ERMI testing can confirm whether your walls are plotting against you. Skip the DIY petri dishes; you need actionable data, not a science-fair experiment.
• Fix the leak, then fix you. Repair water intrusion first, remediate second. Otherwise, toxins simply boomerang back.
• Drainage is queen. Binding agents like charcoal and bentonite help escort mycotoxins out of your system, along with nutrients that support liver function. 
• Sweat like it’s your job. Infrared saunas, hot yoga, or a good old-fashioned jog move toxins through lymph and skin—the body’s built-in haz-mat suits. 
• Mind the mindset. Chronic illness is scary; isolation makes it worse. Dr. Jess nailed the emotional toll. “Sometimes shining your light really brightly can attract moths or parasites, if you will,” she says.

Perhaps the most overlooked aspect of mystery illness is the psychological impact. When you feel terrible but look fine, when tests come back normal but you know something’s wrong, the gaslighting—whether from medical professionals or your own inner critic—can be devastating.

The path forward isn’t about having all the answers immediately. It’s about staying curious and open to possibilities that might not show up in conventional testing. Your symptoms are real, even if the cause isn’t immediately obvious. Sometimes the detective work leads you places you wouldn’t expect, like the air you’re breathing in your own home.