Traumatic Head Injury

A traumatic head injury begins when an external force makes the head and brain move rapidly, often in opposite directions. Acceleration and deceleration can shear neuronal connections, disrupt small vessels, and produce intracranial bleeding. The immediate damage is called primary injury; it cannot be reversed after the event. Secondary injury develops afterward. Bleeding and cerebral swelling occupy space inside the rigid skull, increasing intracranial pressure and reducing cerebral perfusion. Hypoxia and hypotension intensify this process because injured brain tissue has little tolerance for reduced oxygen or blood flow. This is why airway support, adequate breathing, and circulation are neurological interventions—not merely general resuscitation steps. A patient may initially be awake and speaking, then become progressively drowsy as a hematoma enlarges. A normal first conversation does not cancel the significance of the mechanism, anticoagulant exposure, repeated vomiting, or a worsening symptom trend. Concussion is a form of mild traumatic brain injury in which symptoms may occur without a visible lesion on CT; a normal scan therefore does not make persistent confusion or deteriorating function harmless.