How do you know if there is hidden mold in your house?

Author: Fae Lowe DVM  |  Last update: Monday, August 11, 2025

If you don't see signs of mold, but you can smell it, it may be hidden in your walls. A musty smell indicates that mold is growing in your home. The smell of mold feels earthy, like rotting leaves or decaying wood in a dense, damp forest.

How do I test my house for hidden mold?

Home testing kits are typically petrie dishes that you place in a location where you suspect harmful mold might be growing. The dish is meant to collect spores over the course of 24 to 48 hours and then grow the spores into mold, which is then evaluated by a lab or visually inspected.

Can you have mold in your house and not see it?

Yes, mold can be present in your house without being visible, especially in hidden areas. Watch for signs like musty odors, allergic reactions, and past water damage. Regular inspections and addressing water issues promptly are key.

How can I tell if unseen mold is making me sick?

If you have a stuffy nose, sneezing, watery eyes, shortness of breath, wheezing or other bothersome symptoms that persist, see your doctor.

What are the first signs of mold in your house?

You can usually see or smell a mold problem. Mold can appear as slightly fuzzy, discolored, or slimy patches that increase in size as they grow. Most molds produce musty odors that are the first indication of a problem. Mold can grow anywhere there is adequate moisture or a water problem.

9 Signs You Have Toxic Mold In Your Home

How to tell if mold is behind walls?

How to Detect Mold in Walls
  1. Water stains.
  2. Dark rings.
  3. Discoloration.
  4. Deterioration like peeling, bubbling, or cracking of the paint or wallpaper.

What are the 10 warning signs of mold toxicity?

However, some common signs that may indicate mold exposure include: Coughing, wheezing, shortness of breath, nasal congestion, and frequent sinus infections. Rashes, itching, burning sensations, and persistent skin irritation.

Can mold behind walls make you sick?

It irritates the nose and throat, which can lead to both sneezing and coughing as your body tries to get rid of the irritant. Inhaling mold spores can also trigger coughing in people with allergies or an asthma attack, for those with asthma.

How do I test myself for mold exposure?

There are several methods available to test for mold exposure:
  1. Blood Tests: Blood tests for mold exposure detect specific antibodies produced by the immune system in response to mold exposure. ...
  2. Skin Prick Tests: This method involves exposing the skin to small amounts of common molds to check for allergic reactions.

How to tell if your house is toxic?

If you suspect your asthma worsens or is more severe than usual, contact your doctor or medical professional.
  1. Bad Smells In The Home. When there's a bad smell in the home, you can tell. ...
  2. Peeling Wallpaper. ...
  3. Spots On The Wall. ...
  4. Bad Allergies Won't Go Away. ...
  5. Visible Mold Growth. ...
  6. Past Water Damage.

How to check for mold in the air in your house?

The two most common methods used to identify a mold problem are mold test kits or air testing sensors. These kits include the necessary air test devices, chemical strips, or Petri dishes and are available at department stores or online. They'll also come with an instruction manual for any brand-specific guidelines.

What kills hidden mold?

Using Hydrogen Peroxide to Kill Mold

Hydrogen peroxide kills mold effectively on materials such as clothing, floors, bathroom fixtures, walls and items such as kitchen appliances. Pour 3% concentration hydrogen peroxide into a spray bottle. Spray the moldy surface completely to saturate the area with hydrogen peroxide.

How long does it take to get sick from mold exposure?

According to the CDC, people usually experience their first symptoms within 2 to 9 hours of their first exposure. On the other hand, some people could go for weeks or months before feeling sick if their exposure is limited enough. This is why it is also important to check damp, dark areas of your home for mold.

How do I permanently get rid of mold in my house?

Spray the area with a mixture of water and vinegar - half water, half vinegar. Next, scrub to remove all traces of the mold. For removal of black and white mold, spray the area with the half water and half vinegar solution.

Is there a device that detects mold?

Mold Detection

In the same way that smoke detectors identify smoke, not fire, the Biomatrix Mold Monitor identifies unseen moisture that can lead to widespread mold growth.

Does homeowners insurance cover mold?

Homeowners insurance doesn't usually cover mold damage or removal unless it's the result of a covered peril. If the mold in your residence was caused by something sudden or accidental, such as a bursting pipe or some other covered incident on your policy, you may be protected.

What are symptoms of black mold exposure?

The most common symptoms of black mold exposure include:
  • Sneezing.
  • Coughing.
  • Nasal congestion.
  • Postnasal drip.
  • Red eyes.

What kills mold in the body?

Activated Charcoal: Absorbs toxins, potentially helping to clear mold spores from your system. Take it in capsule form to absorb toxins. It's best used under medical supervision, especially after known mold exposure.

How can a homeowner test for mold?

Checking if It Is Mold or Dirt/Dust
  1. Dip a clean cotton swab into a diluted bleach solution and dab it on your wall. If the area brightens after a while, it is mold. ...
  2. It is mold if you smell something earthy, damp, or musty. ...
  3. If you can wipe the spots off easily, they're just dust particles.

Do air purifiers help with mold?

Mold is an obvious health risk in any home, but investing in an air purifier can help limit your exposure. The best among them will ideally offer HEPA-level filtration, with this level of filtration being able to trap up to 99.97% of airborne particles down to 0.3 microns in diameter.

How to find hidden mold in your house?

11 Signs of Hidden Mold You Should Look Out For
  1. Visible Mold Spores. Seeing mold spores in your home is obviously the most noticeable sign of mold infestation. ...
  2. Dark Spots on Surfaces. ...
  3. Musty, Damp, or Earthy Smell. ...
  4. Allergic Reactions. ...
  5. Struggle With Respiratory Issues. ...
  6. Your HVAC System Smells Weird. ...
  7. Warped Walls. ...
  8. Dark Tile Grout.

What are the symptoms of mold in the gut?

Mold exposure has been linked to various gastrointestinal symptoms, including nausea, vomiting, diarrhea, abdominal pain, and bloating. These symptoms can range from mild discomfort to more severe digestive disturbances, depending on the individual's sensitivity and the extent of mold exposure.

What are the neurological symptoms of mold?

Mold exposure can cause a variety of neurological effects, including headaches and migraines, cognitive impairments, memory loss, confusion, impaired motor skills, depression, and other behavioral changes. Due to mold exposure, people with weakened immune systems may be more susceptible to neurological symptoms.

Can mold cause an ear problem?

In some instances, allergic reactions may trigger ear infections. Most commonly, it is reactions to environmental allergens such as mold or pollen that cause infection. Secondhand tobacco smoke can also cause allergic reactions and block the delicate Eustachian tubes.

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