The BTS/SIGN 2016 guideline has reviewed the evidence and offers a structured approach to suspecting and confirming a diagnosis, which is illustrated below. When assessing your patient, you should begin by classifying them into high, intermediate and low probability of asthma using the structured clinical assessment.

As we know, the application of asthma diagnosis in clinical practice can be particularly challenging. We can use the Diagnostic Algorithm to categorise our patients into high, intermediate and low probability of asthma. If you aren’t able to find objective evidence of a diagnosis of Asthma using the various methods available in practice, you should refer to a specialist for a second opinion.