Medicine in the Middle Ages was basic and was based on the ideas of Galen and of the Catholic Church.

Beliefs about Cause & Cure:

Disease was sent by God;
Illness was caused by lack of balance amongst the humours (blood, phlegm, black bile and yellow bile).
Astrology - movement of the planets;
Miasma - posionous vapours in the air (in the later Middle Ages)

There was no progress in the explanation of the cause of disease in this period because of:

Religion - the Catholic Church controlled education and rejected new ideas; they also promoted the ideas of Galen as his theories supported the idea that the human body had been designed by God;
Government was weak and spent little money on health;
Poor communication – roads were poor and travel was dangerous so ideas did not spread;
Poverty
War - books and libraries were destroyed.

GCSE Health and the People AQA

Explanation of Cause and Cure in the Middle Ages