Most urban centres in the middle ages had hospitals and the founding of these was often the result of lay action. It was one of the ‘works of mercy’ to visit and care for the sick, but also to harbour the homeless, so that some institutions were to house wayfarers, and in Durham of course there were always pilgrims. Durham had several hospitals but the most important in the city itself were run from the monastery.

Hospitals proper, as opposed to hospices, were usually founded in the first place to house lepers, suffering from what we would now call Hansen's disease, though it may not have been so readily diagnosed in the high middle ages. In Durham, as in the rest of England, the founding of hospitals seems to have been connected with an epidemic of leprosy which spread from China to Europe from the eleventh century. The disease was greatly feared and hospitals were often founded outside the walls of settlements so that their inmates could be segregated. By the later middle ages lepers in Durham, as elsewhere, were fewer (or were not so often housed in hospitals) and the institutions founded for them had either closed or were given over to the care of the poor or the old. There still were people called ‘lepers’, as one can see from a litigant in the prior's archidiaconal court in 1436 called John Croxton lazarus, but there is little evidence that they were in hospital (Langley clearly thought lepers might be difficult to find) and certainly they were not segregated.