The difference between acute and chronic subdural hematoma is mainly based on the patient’s symptoms, such as the urgency and severity of the onset of symptoms, and the different manifestations of cranial CT based on imaging. In the case of acute subdural hematoma, most patients have a history of acute head trauma or head collision, sudden onset of headache with nausea and vomiting, and in some cases, mental disturbance, and at this time, a cranial CT examination can reveal a high-density subdural lesion, which is mainly hemorrhagic. In the case of chronic subdural hematoma, especially in the elderly, many patients do not have obvious symptoms of headache, but mainly have weakness or poor mental status, and some have cognitive impairment, and the CT examination of the head shows mainly a subdural isodensity or mixed density lesion.