Blood Ministration

Blood Ministration is the process of curing disease and ailments in Barovia through blood transfusion and blood-letting. Blood transfusion is generally the process of receiving blood or blood products into one's circulation intravenously. Bloodletting (or blood-letting) is the withdrawal of blood from a patient to cure or prevent illness and disease. "Bleeding" a patient to health was modelled on the process of menstruation.
The Blood Church has absolute authority over this profession as only those within the church can learn the trade. And even then, only specialized doctors who dedicate themselves fully to the church are allowed to practice the art, resulting in only a handful of specialists in the city capable of practicing.