In chapter 1 the events that may lead up to a diagnosis of dementia are discussed. This phase in the dementia journey is called pre-diagnosis. The research evidence relating to the pre-diagnosis period is summarised and related to the difficulties that a person living with dementia may experience before they receive a diagnosis, and the concerns of family members are discussed. This chapter demonstrates that the journey of dementia begins before a formal diagnosis is given and that this can be a traumatic time for all concerned. There has been an increased policy drive internationally for people living with dementia to help support the move for individuals to receive an earlier diagnosis and local strategies and implementation plans to help make these drivers a reality. In the very early days of dementia the person affected gradually becomes aware that there is some kind of change, this may present as an intuitive feeling. As time passes the person begins to think that something may be wrong particularly where the difficulties become more frequent, noticeable or start affecting everyday life. Early detection, diagnosis and intervention for people with dementia and their carers may also help reduce costs and improve quality of future care. The research relating to pre-diagnosis therefore is largely exploratory to identify potential risk factors and biomarkers indicating potential dementia. The research evidence on the experience of pre-diagnosis for those with concerns about their wellbeing is relatively limited.