I am sorry about your girlfriend's vomiting
blood. She needs to be in an Emergency department as soon as possible if she has not done so already. Vomiting blood is always a medical emergency and should be taken seriously. Even if she feels fine now, it would be best to be evaluated by a doctor
to rule out any slow bleeding
or internal trauma. Her vomiting blood indicates that her internal organs might have been damaged. She needs to go to the hospital and be scanned for internal injuries. There is not an easy way to tell if her vomiting blood is life threatening or not. A thorough evaluation by a doctor can determine the possible cause of this. True vomiting blood mostly comes from internal bleeding of our upper digestive system that has many blood vessels that can rupture and bleed. These areas may include our mouth connected to the food pipe at our throat that goes down and meets our stomach which opens into the upper part of our intestines. The trauma of the punch can cause a tear in the small blood vessels and bleeding in the stomach or the upper part of the intestines. If she has vomited a lot of blood, she may need emergency treatment. Please seek medical help without any delay.