Blood Inside the Mouth, Ear, or Nose - Jurisprudential Answers - Book of Purification

Ahmed al-Hasan Response:

Blood that comes out of blood vessels as a result of a wound or bleeding is impure, even if it is in the mouth, ear, or nose. It is not permissible to swallow blood that is bleeding in the mouth. The mouth may be purified by washing it with water, or without water by spitting out the blood in it; if the remaining trace of blood is absorbed and disappears into the fluids in the mouth, the mouth is judged pure. The same applies to the nose.