Epidural, as the name suggests, is the extradural space, which is a narrow space outside the dura mater under the inner plate of the skull. The subdural is the space under the dura mater, outside the brain tissue, and this space is larger than the epidural. Since the subdural is directly in front of the brain tissue, hematomas and other lesions in the subdural can cause more severe symptoms than those in the epidural. The most common disorder of the epidural is the epidural hematoma, which is formed when the broken end of an epidural fracture punctures a blood vessel in the dura mater. Subdural hematomas, on the other hand, are usually caused by bleeding from the surface of the brain tissue that leaks into the subdural, often in combination with cerebral contusions, and therefore have significantly more severe clinical symptoms than epidurals.