Dyscrasia
（重定向自Eucrasia）
Dyscrasia (or dyskrasia) is a concept from ancient Greek medicine, meaning bad mixture.
The concept of dyscrasia was developed by the Greek physician Galen (129–216 AD), who 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 among these basic components, called eucrasia. Disease was interpreted as the disproportion of bodily fluids or four humours: phlegm, blood, and yellow and black bile. The imbalance was called dyscrasia.