Exsanguination
Acidosis means that the body makes too much acid.  Usually, the body makes energy out of oxygen carried in the blood and glucose (sugar); this is called aerobic respiration. If a person loses a lot of blood, there will not be enough oxygen in the blood that is left to make energy this way. The body switches to anaerobic respiration and makes energy out of glucose without needing oxygen. However, this creates many acidic waste products (chemicals that the body does not need, which are left over after the body does chemical reactions). Eventually, these waste products can build up so much that they poison the body. This is called acidosis.