The two major types of stroke are ischemic stroke (75%), which results from vessel occlusion due to atherosclerosis, thrombosis, or embolism, and hemorrhagic stroke (15%), which results from bleeding into the brain tissue (intracerebral) or into the subarachnoid space due to hypertension, tumor, vascular malformations, or bleeding disorders due to anticoagulant therapy. Lacunar strokes, also known as a small vessel stroke, occur in smaller arteries and are associated with hypertension and diabetes mellitus. They are more likely to cause motor and sensory deficits.

CVA remains the third leading cause of death and is the major cause of disability in the United States, despite a general decline. What has probably contributed to the decline is an increased awareness of risk
factors, improved prophylactic measures such as therapeutic life-style changes, improvements in pharmaceutical therapies, and surveillance of those at risk.