The four humours

The theory about the four humours was important in medicine.
The four humours were body liquids blood, phlegm, yellow bile and black bile. These were connected to the four seasons.
Yellow bile= summer
black bile= autumn
phlegm= winter
blood= spring.

Hippocrates said if someone had a fever in spring then they had too much blood and they had to 'Bleed' the patient.