According to the Army's Task Force Report, up to one in five soldiers returning from combat in Iraq and Afghanistan has a mild brain injury. The report also says that as many as 20 percent of the soldiers have had a concussion but many not even know it.
Concussion is the most common brain injury and it can happen when a powerful blast shakes the brain inside the skull. Symptoms of concussion include headaches, dizziness, irritability, and sleep disorders. The Army is now screening every returning soldier for a hidden concussion injury.