Closed head injuries occur when a blow to the head causes damage to the brain without breaking the skull. These injuries can result from falls, sports accidents, or vehicle collisions. Symptoms may include headaches, confusion, dizziness, and memory problems. Diagnosis often involves imaging tests like CT scans or MRIs to assess brain function and detect any swelling or bleeding. Treatment varies based on the severity of the injury and may include rest, medication, or rehabilitation. It's important to monitor symptoms, as complications can arise even days after the initial injury.