Musty, earthy, or damp smell
Visible black, green, white, or gray spots on walls, ceilings, floors, or furniture
Water stains, discoloration, or peeling paint
Warped, bubbling, or peeling wallpaper
Damp or humid areas, especially bathrooms, kitchens, basements, and attics
Condensation on windows or walls
Recent leaks, flooding, or water damage
Soft, crumbling, or rotting drywall, wood, or trim
Mold growth around sinks, tubs, toilets, vents, or under carpets
Allergy symptoms that improve when leaving the house
Use of a home mold test kit or professional inspection if signs are unclear