Free and equal access to medical treatment has been a staple of the Danish welfare state, but more and more Danes express the view that people treated for lifestyle diseases like smoker's lungs or obesity should pay for their own treatment – as these patients are thought to be responsible for their own medical conditions. The logic behind this view is, however, dubious, says PhD Martin Marchman Andersen from the University of Copenhagen. In a new thesis, he shows how difficult it is to defend the claim that people are responsible for their health and that it is very unclear what they should be held cost-responsible for.