Why do I smell mold in my house but can't find it?

Author: Jon Johnson  |  Last update: Tuesday, September 16, 2025

Note: The presence of a moldy smell in your house doesn't always indicate mold infestation. If you can't find where the smell is coming from, check for rotting food items, wet laundry, and other potential sources of the odor first. Also, open your windows to air out the area.

What to do if you smell mold but don't see it?

When a homeowner smells mold but visual clues are invisible to the naked eye, then mold testing can be performed by a professional to locate the colonies. A mold testing kit can also be inexpensively purchased from the local hardware store and utilized by the homeowner.

What can smell like mold but not be mold?

Check humidity: Musty odors can often be due to excess moisture. Use dehumidifiers to reduce humidity, especially in rooms such as the bathroom, basement or other damp areas. Cleaning: Thorough cleaning is crucial. Clean carpets, curtains, furniture and other surfaces that absorb moisture regularly.

Why does my house randomly smell like mold?

If you smell mold but can't see it, it could be growing behind drywall or wallpaper, under wood paneling, or in walls near pipes. It also could be under carpeting or ceiling tiles, or inside air ducts. Mold grows where there's lots of moisture, like under a sink with a leaky pipe or in a poorly ventilated bathroom.

How do you find where a mold smell is coming from?

Leaks are common in doorways and windows that open to the outdoors, which can lead to dampness and in turn lead to mould. Entrances to the home are therefore a likely to be a source of damp smells, so try to check around the doorway for signs of mould.

9 Signs You Have Toxic Mold In Your Home

Why do I keep randomly smelling mold?

An olfactory hallucination, known as phantosmia, makes you detect smells that aren't in your environment. The odors you notice in phantosmia are different from person to person and may be foul or pleasant. You may notice the smells in one or both nostrils.

What are signs of mold sickness?

Although symptoms can vary, the most common symptoms seen in people exposed to mold indoors include:
  • Nasal and sinus congestion.
  • Eye irritation, such as itchy, red, watery eyes.
  • Wheezing and difficulty breathing.
  • Cough.
  • Throat irritation.
  • Skin irritation, such as a rash.
  • Headache.

Is it bad if I can smell mold in my house?

A moldy odor suggests that mold is growing in the building and should be investigated. The health effects of inhaling mVOCs are largely unknown, although exposure to mVOCs has been linked to symptoms such as headaches, nasal irritation, dizziness, fatigue, and nausea.

How to detect where a smell is coming from?

If odors seem to be emanating from this part of your home, check the following locations:
  1. Trash Cans. Under counter trash cans are a frequent source of odors. ...
  2. Ovens. Baked-on foods in your oven can cause burning or smoking odors when your oven is in use. ...
  3. Cooktops and Hoods. ...
  4. Disposals. ...
  5. Dishwashers. ...
  6. Refrigerators. ...
  7. Cabinets.

What does a dead mouse smell like?

A decomposing mouse smells like propane gas or rotting meat.

Can you smell mold behind walls?

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 to find hidden mold in your house?

Most often, a mold problem will be readily identified by a musty smell that becomes obvious in damp environments. Mold also likes to play hide and seek, so if you suspect there is a problem, then check under carpets, behind drywall, inside ductwork, in between bathroom tiles and in other moisture-prone areas.

What can be mistaken for mold?

Many confuse mold and mildew, which is not surprising — they have more than a few things in common: Both are types of fungi that no homeowner likes to see in his or her home. Both are keen on forming in moist, warm areas.

What smells like mold but isn't?

Water leaks: Leaks from air conditioning units and plumbing issues are common causes of damp odors in indoor environments. You want to look for signs of moisture around pipes, P-traps and drains in rooms or areas with musty smells.

How do you know if mold is in your walls?

Mold can also grow behind wallpaper or inside the walls. “The main visible sign of mold growth is the discoloration of the wall; even if you paint over it, mold will persist and continue to show signs on the surface,” Rubino warns.

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.

Why do I smell mold when there is none?

Phantosmia refers to detecting smells that aren't really there. It's a symptom of many common conditions, including allergies, colds and upper respiratory infections. It could also indicate a brain-related condition, including epilepsy, stroke or Alzheimer's disease.

What is your nose detecting when you smell something?

When you smell an odor, you're actually breathing in tiny molecules. These molecules stimulate specialized nerve cells, called olfactory sensory neurons, high inside the nose. There are a few million of these cells inside your nose.

How to find where damp smell is coming from?

Check under sinks and taps for a build up of water or leaks that may have caused mould growth. Check for damp patches or any signs of water damage. This could suggest that penetrating damp is causing the damp smell or mould growth.

Why am I randomly smelling mold?

Possible causes range from nasal polyps to a stroke. Phantosmia is also called a phantom smell or an olfactory hallucination. Causes include problems with the nose, such as sinusitis, or conditions of the nervous system or brain, including migraine, stroke, or schizophrenia.

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 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 do you test for mold in your house?

Air sampling is the most common type of mold testing. It involves collecting air samples from various areas of your home and analyzing them for the presence of mold spores. Air sampling can identify the type and concentration of mold spores in your home.

What happens if you breathe in mold for a long time?

Chronic Fatigue: Mold forces your body to work harder, leading to persistent fatigue, especially in those with pre-existing conditions. Lung Issues: Prolonged exposure can cause lasting damage to lung function.

What does black mold smell like?

Toxic black mold growth has a more potent and identifiable smell, like the smell of decay, wet soil, or rot. Visually, it may be greenish-black, grayish-black, slimy, or more furry than other forms of mold or mildew.

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