A concussion occurs when your head receives considerable impact causing your brain to become jolted or to bounce inside your skull. Concussions are typically classified as mild traumatic brain injuries. However, they should be taken seriously and treated immediately by a medical professional, as all TBIs can lead to life-long consequences. An untreated concussion may lead to serious repercussions, and may be fatal. Traumatic brain injuries (TBIs) will be classified based upon severity and may range from moderate to severe.