Which is the most dangerous type of intracranial hematoma, and why?

Subdural hematoma.

Subdural hematoma commonly results from bleeding due to a fracture of skull bone and severe complications of traumatic head injury and whose symptoms appear immediately. The bleeding is very slow which causes a buildup of blood in the brain and swelling of the brain which brings pressure leading to breathing problems or even death if no immediate action is taken. It is the very dangerous especially in children because in most cases it causes unconsciousness and can cause a lasting brain damage and it may take many years to heal.

References.

Abdulrahim, H. H. (2019). Association between skull fractures and types of intracranial hematomas in children with head injury. Zanco Journal of Medical Sciences (Zanco J Med Sci), 23(1), 100-105.

Li, Z., Xu, F., Li, Y., Wang, R., Zhang, Z., & Qu, Y. (2020). Assessment of intracranial pressure monitoring in patients with moderate traumatic brain injury: A retrospective cohort study. Clinical neurology and neurosurgery, 189, 105538.