What's That Smell in My House?

Figure out the likely causes of unpleasant smells in your home.

U.S. News & World Report

What's That Smell in My House?

Young woman at home smelling something stinky and disgusting, intolerable smell, holding breath with fingers on nose. Bad smells concept.

Weird smells in your home can range from pungent to dangerous.(Getty Images)

You walk in the front door and something smells off. Is it trash? Dirty clothes? Something worse?

A weird smell in your house can be caused by something as benign as old food that needs to be thrown away, but it could reveal a dangerous gas leak, fire or pest problem.

Here’s what you may be smelling in your house, and the potential causes:


Where there’s smoke, there’s fire. Cooking over an open flame, burning candles or using your fireplace can increase your chances of starting an accidental fire that can damage your home and spread quickly if not put out. It’s a good idea to have a fire extinguisher on hand in case a fire starts.

However, the electric wiring throughout your home can also become a fire hazard if it’s old, misused or becomes damaged. The U.S. Fire Administration reports there are about 45,000 home electrical fires per year, and half of them involve lighting or electrical wiring. An electrical fire in your home can start in walls, outlets or appliances. If you see smoke coming from an overloaded power strip or appliance and can safely unplug it, do so.


Not all fire hazards smell like smoke. If your nose is catching a fishy smell and you haven’t cooked any fish, it could be a sign of electrical components overheating, which can lead to an electrical fire. Wires, plastic and other parts of a circuit can give off a fishy smell when they’re getting too hot and starting to burn.

Rotten Eggs


If you’re smelling rotten garbage, it probably is rotten garbage and you should take it out. If the smell doesn’t appear to be coming from your trash can, go shelf by shelf in your refrigerator and pantry to identify whether food has gone bad. Also check dirty dishes and countertops, and turn on your garbage disposal with the water running and pour some dish soap down the drain.

Oily Smell

A dirty, oily smell is often associated with a cockroach infestation. This oily smell may be from the pheromones that cockroaches produce to attract a mate or inform others of a food source.

However, Hartzer notes that the most potent smell to lead you to cockroaches isn’t their pheromones. “Typically, what people are smelling when they have cockroach issues is that food source,” she says.

Animal Urine

If you’re smelling animal urine or feces in a part of your home and there’s no way a pet had an accident, you may have a wild animal inside your home. Mice and rats aren’t likely to give off a potent odor if they’re just scurrying by, but you’re more likely to smell their urine and feces in places they congregate – either at a food source or nest.


If your house or a specific room has a continuous stuffy, musty scent, you’re likely smelling mold.

Mold can grow just about anywhere in the home where moisture can get in, although attics, basements and crawl spaces are the most common areas to see mold, says Greg Bukowski, founder and CEO of Moldman, a professional mold abatement company in Chicago.

In places where you don’t see mold, it’s possible the growth is occurring behind your walls. In this case, you or a professional will need to cut exploratory holes in the wall to find the source. While you want to remove any and all mold from your home as quickly as possible, you don’t need to evacuate the house – even if the mold is black. A common misconception is that black mold is more toxic to people than other types of mold. While some people may be more sensitive to a certain fungus strain, all types of mold can have negative health effects.

“Really, any type of mold does not belong in a healthy home – treat it all the same. Don’t panic,” Bukowski says.


If you suddenly notice the smell of raw sewage somewhere in your home, it’s likely coming from a drain you haven’t used in a while. It could be the result of a dry P-trap, which is a part of your plumbing that stores a small amount of water to prevent sewer gas from coming into your home.

If you’re smelling sewage from the drain, the P-trap has dried up, likely because the water evaporated after not being used for a long time. Simply pour water down the drain to allow the P-trap to fill again, and be sure to periodically run the water in every sink and tub or shower to prevent evaporation in the future. Open some windows to rid of any lingering sewage smell from your home.

If the sewage smell persists, you may have an issue with the wax seal for your toilet or a backup somewhere in your home. A plumber may be able to diagnose the issue quickly.

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