Atherosclerosis, or hardened arteries, is what stroke and heart disease have in common. Understanding what causes it is a big step in prevention.
According to the American Stroke Association, 83% of strokes are ischemic. An ischemic stroke occurs when a blood vessel or artery leading to the brain becomes blocked. This blockage results in oxygenated blood being prevented from reaching parts of the brain. While there are two types of ischemic stroke, those caused by either a thrombosis or embolism, the focus of this article is on thrombotic strokes.
Cerebral Thrombosis Stroke
Cerebral thrombosis is a thrombus, or blood clot that develops in an artery that supplies blood to the brain. This type of blood clot can develop in arteries that have been damaged by atherosclerosis. Atherosclerosis comes from long-term fatty-deposit and cholesterol buildup. When this type of stroke occurs, it is frequently during the night or in the morning, when blood pressure is low. Thrombotic strokes can occur in small or large arteries.
- Small vessel thrombosis
Small vessel thrombosis, or lacunar stroke, occurs to small arteries deep within
the brain that branch directly off of a large, high pressure main artery. High blood pressure can damage these arteries, either from the pounding pressure, or from dislodging other small clots.
- Large vessel thrombosis
Large vessel thrombosis is the most common type of thrombotic stroke, and tends to be more severe. This type of stroke is a combination of long-term atherosclerosis followed by rapid blood clot formation. The most common places for these clots to appear are in the carotid arteries, located on either side of the neck. Sadly, according to the National Stroke Association, for a person who has suffered this type of stroke, heart attack is a frequent cause of death since coronary artery disease is also likely.
What is Atherosclerosis?
While some hardening of the arteries occurs naturally with age, atherosclerosis is not a condition that must eventually occur to everyone. It is preventable. Atherosclerosis is a complex condition of plaque buildup that takes many years to develop, but can also be reversed. This plaque is an accumulation of fatty substances, cholesterol, cellular waste products, and calcium, as well as a blood clotting material called fibrin.
A severe buildup of plaque causes arteries to become extremely hard and inflexible. Adding to that problem, as the plaque continues to accumulate, the arteries become narrower in diameter, allowing less blood to pass through to the brain and heart. Narrow arteries require the heart to work harder to pump blood, resulting in a condition known as high blood pressure.
According to Nobel Laureate, Dr. Louis J. Ignarro, in NO More Heart Disease, this decreased blood flow can cause:
- Premature aging and disability
- Impaired memory
- Hypertension
- Senile dementia
- Peripheral artery disease (inadequate blood flow in legs)
- Stroke and heart attack
Stroke Prevention
Prevention of stroke is focused strongly on managing some specific controllable risk factors. According to the American Heart Association, atherosclerosis is greatly influenced by controllable risk factors that include the management of:
- Elevated levels of cholesterol in the blood
- High blood pressure
- Cigarette smoking and exposure to tobacco smoke
- Diabetes mellitus
- Obesity
- Physical inactivity
Take control and stay alive!
References
- American Heart Association
- American Stroke Association
- Ignarro, Louis J. NO More Heart Disease. New York: St Martin's, 2005
