Risk factors

A number of factors can make you more likely to develop a mold allergy or worsen your mold allergy symptoms, including:

• Having a family history of allergies. If allergies and asthma run in your family, you're more likely to develop a mold allergy.
• Working in an occupation that exposes you to mold. Occupations where mold exposure can be high include farming, dairy work, logging, baking, millwork, carpentry, greenhouse work, winemaking and furniture repair.

• Living in a house with high humidity. Having indoor humidity higher than 50% can increase mold in your home.

  Mold can grow virtually anywhere if the conditions are right — in basements, behind walls in framing, on soap-coated grout and other damp surfaces, in carpet pads, and in the carpet itself. Exposure to high levels of household mold can trigger mold allergy symptoms.

• Working or living in a building that's been exposed to excess moisture. Examples include leaky pipes, water seepage during rainstorms and flood damage. At some point, nearly every building has some kind of excessive moisture, which can encourage mold growth.
• Living in a house with poor ventilation. Tight window and door seals can trap moisture indoors and prevent proper ventilation, creating ideal conditions for mold growth. Damp areas — such as bathrooms, kitchens and basements — are most vulnerable.