<unk> -axial hematoma, or<unk> , is a subtype of intracranial hemorrhage, or bleeding within the intracranial space, that occurs within the skull but outside of the brain tissue itself.  All intracranial hemorrhages constitute serious medical emergencies because they can increase intracranial pressure and crush delicate brain tissue, with potentially fatal results.
The category of<unk> -axial hematomas includes:
Epidural, which occur between the dura mater (the outermost meninx) and the skull
Subdural, which occur in the subdural space between the dura and the arachnoid mater
Subarachnoid, which occur between the arachnoid and pia meningeal layers
The other type of intracranial hemorrhages are intra-axial hemorrhages, which occur within the brain tissue itself.
Extra-axial hemorrhage
Intra-axial hemorrhage
Intraventricular hemorrhage
Epidural hematoma
Brain herniation
Intraparenchymal hemorrhage
Subdural empyema
Hydrocephalus