Asthma is caused by hyperreactivity of the airways of the lungs. Common triggers include: colds and infections, so you want to start the asthma medications (albuterol, inhaled cortisone-advair, flovent, pulmocort) when a cold begins. Patients with asthma should also get the flu and pneumonia vaccine. Another trigger is exercise. People with asthma induced exercise may need to predose with an albuterol inhaler. Another trigger is stress.