<Tr> <Th> MeSH </Th> <Td> D006408 </Td> </Tr> <Tr> <Td_colspan="2"> (edit on Wikidata) </Td> </Tr> <P> A subdural hematoma (SDH), is a type of hematoma, usually associated with traumatic brain injury . Blood gathers between the inner layer of the dura mater and the arachnoid mater . Usually resulting from tears in bridging veins which cross the subdural space, subdural hemorrhages may cause an increase in intracranial pressure (ICP), which can cause compression of and damage to delicate brain tissue . Subdural hematomas are often life - threatening when acute . Chronic subdural hematomas, however, have a better prognosis if properly managed . </P> <P> In contrast, epidural hematomas are usually caused by tears in arteries, resulting in a build - up of blood between the dura mater and skull . Subarachnoid hemorrhage, the third type of brain hemorrhages, is bleeding into the subarachnoid space--the area between the arachnoid membrane and the pia mater surrounding the brain . </P>

Where is the mass of blood located in a subdural hematoma