TBI is an injury from some type of trauma, such as a blow, jolt, or penetrating object, that disrupts normal brain functions. Falls, car accidents, impact while playing sports, and objects piercing the skull are common causes of TBI. A TBI can range from mild, sometimes called a concussion, to serious, which can cause long-term problems. NICHD is one of many NIH institutes and other federal agencies working to understand and prevent TBI and to help people recover from TBI and related conditions.