Dyscrasia is a nonspecific term that refers to a disease or disorder, especially of the blood. The latter is called a blood dyscrasia.
Before modern medicine, it meant an imbalance of four body fluids: blood, bile, lymph, and phlegm.
Natelson EA, Chughtai-Harvey I, Rabbi S. Hematology. Rakel RE, Rakel DP, eds. Textbook of Family Medicine. 9th ed. Philadelphia, PA: Elsevier; 2016:chap 39.