Prevalence and factors associated with fatigue in the Lausanne middle-aged population: a population-based, cross-sectional survey.

In a population-based sample aged 45-86, fatigue was present in one out of five subjects. Regarding clinical factors, sleep disturbances such as insomnia and sleep apnoea should be assessed first, followed by depression. Regarding biological factors, anaemia should be ruled out, while screening for hypothyroidism is not recommended as a first step. Sleep complaints and fatigue in older subjects are not due to ageing and should prompt identification of the underlying cause.