arterial or venous rupture depending on the locations. Arterial injuries results in more rapidly growing hematoma when compared to venous injuries. At the pterion region, middle meningeal artery is most commonly affected. When fracture is crossing areas where dural venous sinuses resides, venous hemorrhage can occur such as falx cerebri, tentorium cerebelli, and vertex (where superior sagittal sinus resides). Anterior temporal EDH is usually caused by sphenoparietal sinus. Such EDH is limited and does not require surgery because its extension is confined within sphenosquamosal suture and orbital fissure. In 20 to 50% of epidural hemorrhage cases, there is a lucid interval where a person regained consciousness after being knocked unconscious and then followed by deterioration of consciousness after that. When the epidural hematoma is large enough, it will cause mass effect on contralateral brain which lead to midline, subfalcine (below the falx cerebri), and trans-tentorial (crossing tentorium cerebelli) herniations. This phenomenon can cause the subject to lose consciousness and eventually death. Therefore, large EDH requires emergent surgical clot evacuation. Embolisation of middle meningeal artery is performed if the hemorrhage is medium or small. Subdural hemorrhage Subdural hemorrhage (SDH) results from tearing of the bridging veins in the subdural space between the dura and arachnoid mater. It can cross the suture lines, but not across dural reflections such as falx cerebri or tentorium cerebelli. Therefore, subdural hematoma always limited to one side of the brain. Density of SDH reduces as it progresses from acute to chronic forms. However, areas with low density may not represent chronic SDH entirely as unclotted blood products that are due to active bleed can also give low density appearance on CT scans especially those with coagulopathy. Those with SDH that have same density with brain parenchyma may represent acute bleed such as those with anemia, arachnoid tear, and the mixing of hemorrhage and CSF. SDH usually have high or mixed densities during first two days of trauma, followed by isodensity at 11 days after trauma, and hypodensity after 14 days of trauma. Membranes with granulation tissue can rupture within SDH, and give high density appearance on CT scan. Over a prolonged period of time, calcifications can form. SDH can be treated with burr hole drainage, craniotomy or port system placement for blood clot evacuation, or middle meningeal artery embolisation. Subdural hematoma maybe less acute than epidural hematoma due to slower blood accumulation, but it still has