While mold and related microbial agents can be found both inside and outside, specific factors can lead to significantly higher levels of these microbes, creating a potential health hazard. Several notable factors are water damage in buildings, the use of building materials which provide a suitable substrate and source of food to amplify mold growth, relative humidity, and energy-efficient building designs, which can prevent proper circulation of outside air and create a unique ecology in the built environment. A common issue with mold hazards in the household can be the placement of furniture, resulting in a lack of ventilation of the nearby wall. The simplest method of avoiding mold in a home so affected is to move the furniture in question.
More than half of adult workers in moldy/humid buildings suffer from nasal or sinus symptoms due to mold exposure.
Prevention of mold exposure and its ensuing health issues begins with the prevention of mold growth in the first place by avoiding a mold-supporting environment. Extensive flooding and water damage can support extensive mold growth. Following hurricanes, homes with greater flood damage, especially those with more than  of indoor flooding, demonstrated far higher levels of mold growth compared with homes with little or no flooding.
It is useful to perform an assessment of the location and extent of the mold hazard in a structure. Various practices of remediation can be followed to mitigate mold issues in buildings, the most important of which is to reduce moisture levels. Removal of affected materials after the source of moisture has been reduced and/or eliminated may be necessary, as some materials cannot be remediated. Thus, the concept of mold growth, assessment, and remediation is essential in preventing health issues arising due to the presence of dampness and mold.
Molds may excrete liquids or low-volatility gases, but the concentrations are so low that frequently they cannot be detected even with sensitive analytical sampling techniques. Sometimes, these by-products are detectable by odor, in which case they are referred to as "ergonomic odors", meaning the odors are noticeable but do not indicate toxicologically significant exposures.