The Gospel of Luke gives us an accurate description of a very real and yet uncommon medical condition: hematidrosis. It occurs during times of great mental and emotional stress. There are tiny blood vessels that surround all our sweat glands, especially on our brows. When a person is experiencing emotional trauma, the body reacts with a sudden rise in blood pressure. This can cause those tiny blood vessels, which we call capillaries, to burst. The blood then mixes with the sweat.
Like I said, it’s rare. This is most often seen or recorded during times of war as soldiers prepare to go into battle. This makes sense. In battle, they face the real possibility of death. For Jesus, it was not the possibility of death facing Him that night. It was a sure thing. It was a done deal. Jesus had to die for all our sins, transgressions, and iniquities.