No one knows exactly what causes asthma. Asthma tends to run in families and may be inherited, and environmental factors may also play a key role. Scientists continue to explore what causes asthma, but we do know that these factors play an important role in the development of asthma:
Genetics. Asthma tends to runs in families. Genetics play an important role in causing asthma. If your mom or dad has asthma, then you are more likely to have asthma too.
Allergies. Some people are more likely to develop allergies than others, especially if one of their parents has allergies. Certain allergic conditions are linked to people who get asthma.
Respiratory Infections. As the lungs develop in infancy and early childhood, certain respiratory infections have been shown to cause inflammation and damage the lung tissue. The damage that is caused in infancy or early childhood can impact lung function long-term.
Environment. Contact with allergens, certain irritants, or exposure to viral infections as an infant or in early childhood when the immune system isn't fully mature have been linked to developing asthma. Exposure to certain chemicals and dusts in the workplace may also play a significant role in adult-onset asthma.
Reviewed and approved by the American Lung Association Scientific and Medical Editorial Review Panel.
Page last updated: October 23, 2020