Asthma severity and asthma control are two of the more commonly used categorization methods for asthma classification. Direct evaluation of airway inflammation would be the ideal measure of severity, but this is not possible in most situations and other indirect methods are used: patient-reported symptoms, spirometry data, and medication requirements to maintain adequate control. Asthma control, on the other hand, is dissociated from severity as it is determined independently of current medication use. These two classifications are used in establishing the risk of exacerbations, disease progression, and management plan. Advanced biomarkers are being evaluated to assist in a more objective assessment but are not currently used routinely in clinical practice.