The physician Galen (130-201/199 AD) elaborated a model of health and disease as a structure of elements, qualities, humors, organs, and temperaments. Health was understood in this perspective to be a condition of harmony or balance (eucrasia) among these basic components that make up both nature in general and the individual body. Disease was interpreted as the disproportion (dyscrasia) of bodily fluids or four humours: phlegm, blood, and yellow and black bile.