What is the ruling on swallowing blood after tooth extraction, and does it invalidate the fast?

Intentionally swallowing blood is forbidden, whether one is fasting or not, because it is impure. Swallowing it invalidates the fast. Anyone who experiences bleeding from their mouth must spit it out and not intentionally swallow any of it. Whoever swallows it while fasting has invalidated their fast and must make it up. However, blood entering the throat during sleep incurs no sin and does not break the fast, because a sleeping person is not held accountable.