Death due to delayed onset intracranial bleeding in a patient with an acute subdural hematoma

We report a fatal case of acute subdural hematoma (ASDH) involving the delayed onset of subdural bleeding after a head trauma. There were no central nervous symptoms after the head trauma and an initial head computed tomography (CT) scan did not exhibit any abnormal findings. On the second day, the patient suddenly complained of a headache and vomiting, and she lost consciousness. An emergency head CT scan detected a right-sided ASDH and severe cerebral herniation. As the patient was taking triple anticoagulant therapy, surgery could not be performed. She died 2weeks after the onset of the ASDH. Even in cases of head trauma that do not exhibit abnormal findings on head CT, it is necessary to follow up the patient's clinical condition. Specifically, controlling coagulability and performing repeated head CT examinations are considered to be beneficial for preventing abundant subdural bleeding and facilitating the early detection of delayed onset ASDH.