A diagnosis of asthma is based on a patient's symptoms, medical history, a physical examination, and laboratory tests that measure lung function. Your doctor will look for signs that your airflow is obstructed and that the obstruction is at least partially reversible with short-acting beta-agonists (i.e. albuterol).

During an asthma attack, wheezing can be heard by listening to the chest with a stethoscope. The airway obstruction is considered reversible if the wheezing disappears in response to treatment, or when the suspected triggering factor is removed or resolved.