Blood Ministration is the process of curing disease and ailments in Yharnam 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.
Yharnam is the home of blood ministration, a unique but common treatment in Yharnam.
The Healing Church is the fountainhead of blood healing. The church controls all knowledge on blood ministration and all varieties of blood. To the church, Blood ministration is, of course, the pursuit of communion.
The Blood Ministration is performed by the Healing Church and Blood Ministers, who belong to it. Yharnam's blood ministration is said to have the ability to cure all diseases, and thus it attracts all kind of sickly travellers who seek the miraculous blood.
Ever since the beast plague that ravaged Yharnam, the outsiders would have to make a contract to become beast hunters as payment for Blood Healing, if they can not afford it.
However, as the Hunter also witnesses, any patient who receives Yharnam special blood will have a hallucination of a bloody beast crawling towards them. Though the Blood Ministers assure patients that this hallucination is just a "mere bad dream", it is depicted in the surgery altar in the church Research Hall, which proves that the hallucination happens to everyone who imbibes the old blood.
After the Blood Ministration, the patient's health is significantly increased. And the hunter uses blood to enhance their weapons and flesh.
Little do they know, the miraculous blood ministration is the root of the beast scourge.
The Church knows about their blood ministration beastly side effect but they blame the outsiders for the source of the scourge. Their propaganda greatly affected the Yharnamites - long imbibers of blood, turning them hostile towards outsiders. Travellers who are unlucky enough to get caught in the night of the hunt will be killed.
- There are very few women who become beasts in Yharnam: Vicar Amelia-a heavy imbiber of blood and a woman in Forbidden Woods. Perhaps the process of menstruation does effectively expel the infected blood.
- Brador, having witnessed the beast transformation process of his comrade, believes in healing through blood-letting. He also made a special trick weapon- the Bloodletter to expel gained blood.
- There is a carcass of a Blood-starved Beast in Old Yharnam, hung and flayed to harvest Ritual Blood.
- In real life, research into blood transfusion began in the 17th century. However, early transfusions were risky and many resulted in the death of the patient. By the late 19th century, blood transfusion was regarded as a risky and dubious procedure and was largely shunned by the medical establishment. The largest series of early successful transfusions took place at the Edinburgh Royal Infirmary between 1885 and 1892. Edinburgh later became the home of the first blood donation and blood transfusion services.
- It was not until 1901, when the Austrian Karl Landsteiner discovered three human blood groups (O, A, and B), that blood transfusion was put onto a scientific basis and became safer.