The main differences between acute and chronic subdural hematoma: First, in acute subdural hematoma, the patient may show acute headache, nausea, vomiting, and the patient may also have psychiatric symptoms such as indifference of consciousness, irritability, and cranial CT examination may reveal a crescent-shaped high-density foci under the dura; second, in chronic subdural hematoma, the course of the disease is usually more than half a month, or there is no obvious history of trauma, and the patient’s performance is mainly based on symptoms of dizziness, dullness, mild headache, and hyporesponsiveness. The examination of cranial CT may show a subdural mixed density or an isointense lesion similar to brain tissue. In short, one is distinguished by the duration of the disease and the other is mainly based on the presentation of the hematoma on the cranial CT film.