A stroke occurs when blood flow to an area of the brain is cut off and brain cells are deprived of oxygen. A stroke can cause loss of speech, movement, and memory, both permanently and temporarily. Signs of an occurring stroke include sudden numbness or weakness of face, arm or leg, sudden confusion, trouble speaking, or understanding, sudden trouble seeing in one or both eyes, sudden trouble walking or dizziness, sudden severe headache with no known case. There are two different types of strokes that may occur:
i. Ischemic Stroke
Ischemic stroke occurs when a blood vessel carrying blood to the brain is blocked by a blood clot. High blood pressure is the most important risk factor for this kind of stroke. An embolic stroke occurs when a blood clot or plaque fragment forms somewhere in the body and travels to the brain. Once in the brain the clot travels to a vessel small enough to block its passage. The clot lodges there, blocking the blood vessel. A thrombotic stroke is caused by a blood clot that forms inside one of the arteries supplying blood to the brain. This is often seen in people with high cholesterol levels and atherosclerosis.
Ischemic Stroke. National Stroke Association. http://www.stroke.org/understand-stroke/what-stroke/ischemic-stroke
ii. Hemmorrhagic Stroke
Hemorrhagic strokes are less common that ischemic strokes. They occur when a brain aneurysm bursts or a weakened blood vessel leaks. Blood spills into or around the brain creating swelling and pressure, damaging cells and tissue. Intracerebral hemorrhages occur when a blood vessel inside the brain bursts. Subarachnoid hemorrhages involve bleeding in the area between the brain and the tissue covering the brain and are often caused by burst aneurysms.
Hemorrhagic Stroke. National Stroke Association. http://www.stroke.org/understand-stroke/what-stroke/hemorrhagic-stroke
Understand Stroke. National Stroke Association. http://www.stroke.org/understand-stroke