You’ve probably walked into someone else’s home and noticed the lingering scents of last night’s salmon dinner, pet odor, musty bedrooms or slightly mildewy bathrooms. But why is it so hard to tell if your own home smells bad? That’s because, after a while, you stop noticing it.

There’s even a name for it: nose blindness, or olfactory adaptation. But don’t beat yourself up over it. Blame your brain.

Nose blindness is a natural sensory phenomenon where the brain adjusts to — and essentially “tunes out” — consistent or familiar smells over time, Dr. Nick Rowan, an otolaryngologist specializing in rhinology and skull base surgery at Johns Hopkins Medicine, tells Yahoo Life. Dr. Tran Locke, assistant professor of otolaryngology at Baylor College of Medicine, explains that “our brains are wired to detect new smells, which can signal a change in our environment, like the presence of smoke or food. When we’re exposed to a constant smell, like the scent of our house, our brain starts to filter out that smell. This lets us focus on new smells that may occur in the environment rather than get overwhelmed by background smells.”

Moisture is a top culprit when it comes to household odors. “When surfaces and items are exposed to prolonged moisture, they can start to grow bacteria that can lead to mildew and mold growth, and that creates a musty smell,” Carolina Kazimierski, president of Sophia’s Cleaning Service, tells Yahoo Life. “You can find this smell anywhere from your towels to your closets to your drains — wherever moisture is present. Ventilation and regular cleaning are thus the best ways to combat this musty smell.”

In general, the most common sources of odor in homes are the trash can, refrigerator and garbage disposal, as well as carpets, upholstered furniture and pet items, Natalie D’Apolito, communications and outreach coordinator for the American Cleaning Institute, tells Yahoo Life.

So, how can you tell if your home’s aroma is more stinky than fresh, and what can you do to make it smell good? Here’s what experts suggest.