Extract the ways the asthma is classified and create a bulleted list.

Asthma is thought to be caused by a combination of genetic and environmental factors.[4] Environmental factors include exposure to air pollution and allergens.[5] Other potential triggers include medications such as aspirin and beta blockers.[5] Diagnosis is usually based on the pattern of symptoms, response to therapy over time, and spirometry lung function testing.[6] Asthma is classified according to the frequency of symptoms, forced expiratory volume in one second (FEV1), and peak expiratory flow rate.[12] It may also be classified as atopic or non-atopic, where atopy refers to a predisposition toward developing a type 1 hypersensitivity reaction.[13][14]
https://en.wikipedia.org/wiki/Asthma

-Frequency of symptoms
-FEV1
-Peak expiratory flow rate
-Atopic
-Non-atopic