If you have ever bumped your head, then you may have experienced a traumatic brain injury (TBI). TBI is brain damage caused by an outside force. In the long run, TBI may weaken a person’s ability to think, learn, or remember. In this article, we will learn how the mitochondria, tiny structures inside our cells, are partly responsible for the harmful effects of TBI. Mitochondria produce most of the energy our cells need to function properly. This, however, comes with a cost. Energy production is accompanied by the release of harmful substances, such as reactive oxygen species (ROS). ROS can damage components inside our cells and even lead to cell death. In TBI, damaged mitochondria produce high amounts of ROS. Drugs called antioxidants may protect the brain following TBI. Antioxidants can destroy ROS. However, you should never use these drugs without medical guidance.