A bronchodilator is used by almost all people with asthma as a way to open the airway passages.
Short-acting bronchodilators are used as a "quick relief" or "rescue" medication, while long-acting bronchodilators are used every day to control asthma -- in conjunction with an inhaled steroid.
American Academy of Allergy Asthma & Immunology: "What is an Allergy/Asthma Specialist?" American Academy of Family Physicians: "Asthma: Questions to Ask When It Doesn’t Get Better?" Merck Source: "Questions to Ask Your Doctor."