Your body works like a well-oiled machine. When there is even a slight change in the way it functions, there can be negative consequences. With a stroke, there is a change in the amount of blood available to the brain. Parts of the brain won't get the oxygen and nutrients needed to maintain life and the cells can begin to die within 3 to 4 minutes. When those nerve cells die, the part of the body they control cannot function either.
Lack of Blood to the Brain
One of the most common causes of a stroke is a lack of blood supply to the brain. According to the American Heart Association, an ischemic stroke accounts for 87 percent of all strokes. It happens when a blood clot forms in the arteries that feed the brain and blocks the flow of blood to the brain. These blood clots can form along the walls of the arteries when they have been damaged by atherosclerosis. A clot in the artery within the brain is a thrombotic stroke and often happens at night or first thing in the morning. You will often have a warning sign called a transient ischemic attack (TIA) or "mini-stroke" These attacks have the same symptoms as a stroke but only last for a few minutes. A stroke, however, will often leave permanent damage.
Embolism in the Heart
An embolic stroke is also considered an ischemic cause of stroke but the origin of the blockage to the artery is different. According to Mayo Clinic, the blood clot that blocks the area will form away from the brain and travel through the arterial system to the brain. These clots may form in the heart and are caused by an irregular heartbeat. Because the heart is beating erratically there is poor blood flow, reduced oxygen supply and the increased risk that a blood clot will form. As the clot travels out of the heart, it reaches the brain where the arteries are smaller. Here, it lodges and stops blood from flowing past and feeding that area of the brain.
Hemorrhage
The medical term for bleeding is "hemorrhage." A hemorrhagic stroke occurs when the blood vessels that feed the brain leak or rupture and blood leaks into the brain tissue. According to the National Institute of Neurological Disorders and Stroke, this is the second most common cause of strokes in the adult population. These hemorrhages can be the result of several different conditions. Uncontrolled high blood pressure, weakened areas in the arterial walls and head injury are the top reasons for developing this cause for stroke.
