Unani system of medicine is based on the “Humoral Theory” which was presented by
Hippocrates. According to “Humoral Theory”, there are four Akhlaat (humours) in the body-
Dam (blood), Balgham (phlegm), Safra (yellow bile), and Sauda (black bile). Each humour has
its own temprament- blood is hot and moist; phlegm is cold and moist; yellow bile is hot and dry;
and black bile is cold and dry.
Explaining the idea of Greek philosopher Empedocles (d. 430 BC) of the four elementary roots
of all matter- earth, water, air and fire, Hippocrates presented the idea that human body was also
a composition of four elements as blood, phlegm, yellow bile and black bile. In Tibb-e-Unani, a
state of health is called when there is an equilibrium and balance among these four humours and
if there is any imbalance in their original composition, it is called a state of disease.