What Is the Major Cause of Stroke?

A person can suffer from a stroke when there is too much or too little blood in the brain. If there is too little blood, this is called an ischemic stroke. If there is too much blood in the skull, this is called a hemorrhagic stroke.

Expert Insight

• The majority of strokes are ischemic, according to the Mayo Clinic. An ischemic stroke is the result of blocked or narrowed arteries, which compromise the flow of blood to the brain. As a result, the brain cells are deprived of nutrients and oxygen. Cells almost immediately start dying.

Ischemic Types

• Types of ischemic strokes include am embolic stroke, which happens when there is a particle or blood clot in a blood vessel, often in the heart that is carried through the bloodstream and lodges in the narrow brain arteries. A blood clot of this nature is called an embolus and can be caused by irregular beating of the heart in the two upper chambers. When an individual has an abnormal heart rhythm, this can result in the formation of a blood clot and insufficient blood flow.

  The other kind of ischemic stroke is called thrombotic. When a blood clot or thrombus forms in an artery that supplies blood to your brain, a thrombotic stroke can occur. Clots generally form in arteries that are clogged with plaque or fatty deposits. The process can occur in the two carotid arteries of the neck, which carry blood to the brain, as well as in other brain and neck arteries.

Hemorrhagic Types

• Hemorrhage means bleeding. When an individual has an hemorrhagic stroke, this means that there has been a rupture or leak in one of the blood vessels in the brain. High blood pressure can cause this as can aneurysms, which are weak spots in the walls of the blood vessels. Sometimes, the cause is ateriovenous malformation, or AVM, which results in a rupture. The malformation is present at birth and is a tangle of thin-walled blood vessels.

  A subarachnoid hemorrhage stroke is the result of bleeding in a large artery near the brain's surface. The bleed spills into the areas between your skull and the surface of the brain. Those suffering from this type of stroke will probably experience a thunderclap headache, which is severe. Generally, this type of stroke is the result of an aneurysm rupturing. The blood vessels in the brain widen and then narrow erratically when a rupture occurs. This is referred to as a vasospasm, which causes brain cell damage because the blow flow is to the brain is limited.

  An intracerebral hemorrhage happens when a blood vessel in the brain bursts and the blood pours into the brain tissue, which damages brain cells. High blood pressure is generally the cause of this type of stroke.

TIA

• A transient ischemic attack, which is called a mini-stroke or TIA, is the temporary decrease in blood supply to the brain and only last a few minutes. TIAs are generally the result of blood clots; however, a TIA does not do the profound damage that a major stroke does because it doesn't last as long and usually doesn't result in brain damage. However, if an individual is having TIAs, this is an indicator that he is at risk for a full-blown stroke.

Risk Factors

• The risk of having a stroke increases with age. If you have high blood pressure, high cholesterol, a family history of heart attacks, TIAs and strokes, and if you are a smoker, are diabetic, obese or have heart disease, you are at risk. High levels of amino acid in your body as well as taking birth control pills or hormone therapy can increase your risk.