7 Warning Signs Mold in Your Home Is Wrecking Your Health (#7 Is the One Most People Miss)

That constant congestion is usually where it starts. You blow your nose in the morning, breathe clearly for 45 minutes and then feel it clog right back up, and it’s been like that every day for a month.

A stuffy nose is the first symptom on the CDC’s list for mold exposure. And while most people think of allergies as an outdoor problem, the American Academy of Allergy, Asthma & Immunology notes that a mold allergy can also cause symptoms indoors if there’s mold in your home.

The catch is that once you’ve been congested that long, breathing through your mouth starts to feel like your baseline, so you just buy another box of tissues and stop looking for a cause.

When congestion outlasts every cold you’ve ever had, stop treating it like a cold.

Maybe your nose is fine, and the irritation goes straight to your eyes instead. They feel fine when you wake up, start prickling after lunch and look bloodshot by the time you sit down for dinner, so you blame your computer monitor, the ceiling vents or the weather.

NIOSH lists red, itchy or watery eyes as a symptom of mold exposure, and the CDC specifically includes burning eyes on its symptom list. As tiny mold spores drift through a room, they can trigger allergic reactions in sensitive people, and your eyes are exposed to that air every hour you’re awake.

Putting in lubricating drops washes the irritation away for a little while, but the spores are still hanging in the room when the drops wear off.

Eyes that burn or water every single evening are reacting to something, even if you’ve learned to ignore them.

Sometimes it settles lower down, as a dry cough that stays behind long after a winter bug has cleared out. You find yourself clearing your throat all afternoon, or you notice a quiet whistling sound in your chest when you lie down at night and let your breath out.

Respiratory symptoms like these have the heaviest scientific backing in the mold literature. An Institute of Medicine review in 2004 found that damp, moldy indoor spaces are linked to coughing, wheezing and upper respiratory tract symptoms even in otherwise healthy people. And a 2007 analysis by Berkeley Lab and EPA researchers estimated that 21% of current US asthma cases, or roughly 4.6 million, are attributable to dampness and mold at home.

A cough or wheeze that hangs on for weeks needs a doctor’s evaluation and a serious look at your living space.

For a lot of people, the giveaway is a raw throat paired with a heavy, tight feeling behind the eyes and cheekbones. It never quite builds into a full feverish infection, so you don’t stay home from work, but the pressure never completely drains away either.

The CDC names sore throat as one of the symptoms mold can cause, and the American Academy of Allergy, Asthma & Immunology links mold exposure to sinusitis.

Because mold allergy symptoms can look a lot like other respiratory allergies, as the American College of Allergy, Asthma and Immunology points out, most people assume they just have year-round hay fever. You end up cycling through antihistamines, saline rinses and decongestant tablets every month just to keep your head clear.

If you’re buying sinus medication on a monthly schedule, ask an allergist whether indoor mold could be the trigger.

Almost nobody thinks about the air when their skin acts up. You notice an itchy red patch on your forearm or the side of your neck, so you swap out your laundry soap, buy an unscented body wash and put on hydrocortisone, only to watch the irritation creep back 10 days later.

The CDC lists skin rash as a symptom of mold exposure, and the American Lung Association notes that anyone, with or without allergies, can experience irritation of the skin, eyes, nose and throat from indoor mold and dampness.

When a rash keeps returning after you’ve changed your soaps, start asking about the air in the room.

Other people mostly notice it in the mornings. You turn the light off at 10, stay in bed for a full 8 hours and still drag yourself to the coffee maker feeling like you barely slept, with a low ache behind your forehead and a head so sluggish you have to read the same paragraph 3 times.

There’s a straightforward medical piece to that. MedlinePlus, the National Library of Medicine’s consumer site, lists headache, fatigue and irritability as recognized symptoms of allergic rhinitis, and mold is one of the allergens that sets that nasal inflammation off.

People who’ve actually lived with mold in their houses often describe something beyond ordinary tiredness, though, calling it a heavy mental fog that only cleared after they stayed somewhere else or had the house remediated. Because groggy mornings are so easy to blame on work stress, an old pillow or getting older, most people just pour a second cup of coffee and push through it for years.

If 8 hours in bed still leaves you exhausted and headache-prone most mornings, bring it up with your doctor and mention your house.

This is the sign most people miss, because it only shows up when they pack a bag. You go visit family for 4 days or check into a hotel for the week, and by day 3 your sinuses open up, your eyes stop itching and the throat clearing fades out, until you walk back through your front door and feel it all return within 24 hours.

Occupational health researchers at NIOSH use that exact pattern to identify building-related symptoms, defining them as complaints that improve when a person is away from the building. Those studies looked at workplaces rather than houses, but if you notice that shift at home, it’s a clue worth sharing with your physician.

If your symptoms ease when you’re away and come back when you’re home, start with the air in your home.

Paying attention to that pattern matters even more if you have kids down the hall. The World Health Organization notes that children are particularly susceptible to indoor dampness and mold, and a 2011 review in Environmental Health Perspectives found that the evidence strongly suggests indoor dampness and mold make existing asthma worse in children.

Every one of these 7 signs comes down to the air in the rooms where you spend the longest stretches of time, and for most people, that’s the bedroom.