Acute subdural hematoma signs typically appear within how many hours after a head injury?

• A. 24 hours
• B. 36 hours
• C. 48 hours
• D. 72 hours

Answer: (C)

In acute subdural hematoma, the bleeding is venous, coming from torn bridging veins between the brain and skull. Venous bleeding accumulates more slowly than arterial bleeding, so signs and symptoms tend to develop over hours rather than instantly. The typical window for symptom onset is within 24 to 48 hours after the head injury, with about 48 hours representing the common upper limit for the acute presentation. That’s why 48 hours is the best choice.

Clinically, watch for headache, confusion or drowsiness, lethargy, focal neurologic deficits such as weakness on one side, unequal pupil response, vomiting, or deteriorating consciousness as the injury evolves.