Illness in the was explained in many ways; many of which were very unjustified and had no scientific explanation. Firstly, the Four (, black bile, yellow bile and blood) were the reason behind illness. If they were , you were ill and due to and Galen's theories, they used Treatment of . You'd be to reduce blood, cleaned using an enema or made to cough up blood to reduce , made sick (often using salt water) to reduce and to reduce phlegm. This obviously didn't work.

There were many ways to prevent disease in the Middle Ages, including the technique (publicly punishing yourself, begging for ) and people would go pilgrimages to pray at the tombs of . To avoid the disgusting streets, were recruited to clean streets and people would carry to stop the smell affecting them. The biggest prevention was praying, since people strongly believed was responsible for everything. Kings and bishops ordered when disease broke out, praying for the deaths to cease, furthermore, people stopped any activities they felt to be insulting . Some would fast, sacrificing themselves to show God they are for their .

Hospitals were for people who couldn't themselves and rarely admitted the to prevent the spread of . They were also incredibly and were used by people who were most likely to in there.