BackgroundManaging diagnostic uncertainty is a major challenge in primary care due to factors such as the absence of definitive tests, variable symptom presentations and disease evolution. Maintaining patient trust during a period of investigative uncertainty, whilst minimising scope for diagnostic error is a challenge. Mismanagement can lead to diagnostic errors, treatment delays, and suboptimal patient outcomes.ObjectiveOur aim was to explore how UK primary care physicians (GPs) address and communicate diagnostic uncertainty in practice.DesignThis qualitative study used video and audio-recordings. Verbatim transcripts were coded with a modified, validated tool to capture GPs’ actions and communication in primary care consultations that included diagnostic uncertainty. The tool includes items relating to advice regarding new symptoms or symptom deterioration (sometimes called ‘safety netting’). Video data was analysed to identify GP and patient body postures during and after the delivery of the management plan.ParticipantsAll patient participants had a consultation with a GP, were over the age of 50 and had (1) at least one new presenting problem or (2) one persistent problem that was undiagnosed.ApproachData collection occurred in GP-patient consultations during 2017–2018 across 7 practices in UK during 2017–2018.Key resultsGPs used various management strategies to address diagnostic uncertainty, including (1) symptom monitoring without treatment, (2) prescribed treatment with symptom monitoring, and (3) addressing risks that could arise from administrative tasks. GPs did not make management plans for potential treatment side effects. Specificity of uncertainty management plans varied among GPs, with only some offering detailed actions and timescales. The transfer of responsibility for the management plan to patients was usually delivered rather than negotiated, with most patients confirming acceptance before concluding the discussion.ConclusionsWe offer guidance to healthcare professionals, improving awareness of using and communicating management plans for diagnostic uncertainty.