In the United States, more than 22 million people suffer from asthma. Asthma affects people of all ages, but it usually starts during childhood. Nearly six million asthma sufferers are children. There is no one cause of asthma. Instead, the various types are diagnosed based on what triggers an attack. These are the most common types of asthma, along with triggers and characteristics of each:


  • Triggered by allergens like pollen, mites, molds or pet dander
  • Also called seasonal asthma, as it worsens in spring or early autumn


  • Caused by airborne irritants like tobacco smoking, wood smoke, room deodorants, perfumes, air pollution or cooking odors
  • May become worse with respiratory infections, sudden changes in weather or heartburn


  • Caused by exposure to chemicals or animal products in the work place
  • Symptoms appear during working days only
  • May cause redness of the eyes or runny nose


  • Caused by non-allergic irritants, allergens or being in a reclined position
  • Worsens during the night


  • Triggered by exercise or physical exertion
  • Most common in athletes