(See also Overview of Stroke Overview of Stroke A stroke occurs when an artery to the brain becomes blocked or ruptures, resulting in death of an area of brain tissue due to loss of its blood supply (cerebral infarction). Symptoms occur suddenly... read more .)
Most strokes are caused by a blockage of blood flow to part of the brain causing death of brain tissue (ischemia). Such strokes are called ischemic strokes Ischemic Stroke An ischemic stroke is death of an area of brain tissue (cerebral infarction) resulting from an inadequate supply of blood and oxygen to the brain due to blockage of an artery. Ischemic stroke... read more . Only about 20% of strokes are caused by hemorrhage.
There are two main types of hemorrhagic strokes:
Other disorders that involve bleeding inside the skull include epidural hematomas Epidural Hematomas Intracranial hematomas are accumulations of blood inside the skull, either within the brain or between the brain and the skull. Intracranial hematomas form when a head injury causes blood to... read more and subdural hematomas Subdural Hematomas Intracranial hematomas are accumulations of blood inside the skull, either within the brain or between the brain and the skull. Intracranial hematomas form when a head injury causes blood to... read more , which are usually caused by a head injury. These disorders cause symptoms that sometimes resemble those of a stroke.
Bursts and Breaks: Causes of Hemorrhagic Stroke
When blood vessels of the brain are weak, abnormal, or under unusual pressure, a hemorrhagic stroke can occur. In hemorrhagic strokes, bleeding may occur within the brain, as an intracerebral hemorrhage. Or bleeding may occur between the inner and middle layer of tissue covering the brain (in the subarachnoid space), as a subarachnoid hemorrhage.