Asthma is now considered a heterogeneous disease rather than a single airways condition, with distinct endotypes defined by the immunological and inflammatory pathways. These endotypes help to explain the underlying variable clinical presentations, which are defined as phenotypes (Kuruvilla et al, 2019; Holguin et al, 2020). This article examines how the role of the general practice nurse (GPN) can help to identify patients on the asthma register, who have as yet undiagnosed severe asthma and may benefit from targeted biological treatment.