Many factors – genetic, occupational, and environmental – can lead to someone developing asthma. Exposure to things in the environment can also trigger asthma or make symptoms worse. These things include pollen, mold, animal dander, smoke, particulate matter (dust), and gas or diesel fumes. Secondhand tobacco smoke has also been linked to asthma.  

Virginia’s Environmental Public Health Tracking Program provides hospital data and trends about the occurrence of asthma hospitalizations. Asthma hospital admissions tend to be for more severe asthma attacks and do not include asthma among individuals who do not receive medical care or who are treated in outpatient settings.