Asthma is one of the most common diseases of the lung, which can impact the daily life of people at any age. Asthma is a disease of dysregulated inflammation with the physiologic hallmarks of variable airflow obstruction and airway hyperresponsiveness. This disordered response can be triggered by a variety of stimuli, such as allergens, and pollutants. Asthmatic airway inflammation is typically prominently eosinophilic, but there are asthma phenotypes in which eosinophils are lacking, and these patients can prove more challenging to treat. Inhaled corticosteroids remain the mainstay of treatment of asthma and in combination with long-acting inhaled β2-agonists are effective in patients when used as both maintenance and a reliever to treat breakthrough symptoms. If escalating doses of ICS fail to control symptoms, or exacerbations persist, new biologic therapies are now available, which are effective at decreasing the rate of severe exacerbations and represent a targeted approach to asthma treatment.