A hemorrhagic stroke is bleeding inside or around the brain caused by a damaged blood vessel, states Drugs.com. An intracerebral hemorrhage is the most common form, and it occurs when a blood vessel inside the brain ruptures or a weak, abnormal vessel starts to leak.
A subarachnoid hemorrhage causes blood to pool at the brain's surface and flood the subarachnoid space, the area between the brain and the skull, according to Drugs.com. The mixture of blood and cerebrospinal fluid places harmful pressure on the brain, increasing the risk of triggering arterial spasms and permanently damaging brain tissue. A subarachnoid hemorrhage is caused by a leaking aneurysm or arteriovenous malformation.