Most of us spend a significant amount of time indoors, whether we’re at home, work, or school. Although being indoors keeps us away from harmful outdoor pollutants, the air we breathe indoors could make us susceptible to a particular illness — sick building syndrome (SBS). In BrainStuff - HowStuffWorks' video, “What Is Sick Building Syndrome,” host Cristen Conger explains the syndrome is the combination of biological and chemical contaminants, along with poor air ventilation, that lead to “discomforting health effects” linked to the time spent in a building.

The Environmental Protection Agency (EPA) acknowledges SBS to be real, although no specific cause can be found. SBS development is linked to an oil embargo that took place in the 1970s, which led buildings in the U.S. to be made more air tight, so the nation could conserve energy, and building owners could cut costs. Sealing up buildings helped to reduce ventilation down to 5 cubic feet per minute per person. Since then, the American Society of Heating, Refrigeration and Air-Conditioning Engineers, has revised their modern ventilation standards to a minimum of 15 cubic feet per minute per person.

This means exterior pollutants like exhaust and plumbing fumes — containing things like carbon monoxide, radon, formaldehyde and asbestos — can all enter through poorly located intake vents. Meanwhile inside, we're circulating volatile organic compounds from adhesives, carpeting, cleaning agents, synthetic fragrances and even copy machines.

Symptoms of SBS include headaches, dizziness, nausea, and irritation of the throat, nose, skin, and eyes, among others. A popular misconception about SBS is that people who share the same space as a coworker, family, or classmate will experience the same symptoms. However, there are different signs of illness with SBS that are unique to every person. This leads many people to either be misdiagnosed or not seek help.

Efforts have been made to regulate the acceptable levels of gaseous indoor air pollutants. So you could start by increasing ventilation rates, removing pollutant sources and cleaning the air. The EPA also recommends routine maintenance of HVAC systems. A 2003 study also suggests house plants can absorb air pollutants so you don't have to.

It’s best to be more vigilant with building conditions; monitor your symptoms if you believe them to be SBS-related.