The brain is also referred to as cerebellum. The risk are brain damage and death. If the brain is in a small space in the school held by fluid. If the brain swell it has only a little room to swell, then it will touch the skull and cause bleeding.
A swollen cerebellum is extremely dangerous and requires immediate medical attention. Death is a real danger. Severe brain damage is also possible, including being reduced to a vegetative state. Less severe problems, like speech limitations or memory issues, can also occur. With prompt treatment, there is sometimes no lasting damage.