In the human body there are two carotid arteries that branch from the aorta in the chest and run through the neck to the head to supply blood to the brain. During the aging process plaque, a sticky substance consisting of cholesterol, calcium and fat, can accumulate in the arteries, a process called atherosclerosis. As the plaque builds up the arteries become more and more narrow, eventually interfering with blood flow and resulting in carotid artery disease. In the early stages, a blocked carotid artery may not have any signs or symptoms, but as the disease progresses potentially life-threatening conditions may occur.
Bruit
Bruit is a whooshing sound made by a blocked carotid artery that can be heard when a stethoscope is used during an examination. Not all cases of carotid artery disease will produce bruit, according to the National Heart Lung and Blood Institute; however, the presence of bruit can alert doctors to the problem before more serious symptoms appear.
Transient Ischemic Attack
A transient ischemic attack (TIA), often referred to as a "mini-stroke", is usually the first sign of a blocked carotid artery. A TIA can last from a few minutes to an hour, according to information provided by the National Heart Lung and Blood Institute. TIAs are similar to strokes except that the symptoms of a TIA often subside on their own without medical intervention.
The classic symptom of a TIA is weakness, numbness or tingling on one side of the body. The patient may also experience the inability to control the movements of his limbs. Vision impairments that many describe as a window shade being pulled down over the eye are also frequent. Speech and the ability to understand others may also be impaired. Patients having a TIA may also have a sudden and severe headache and dizziness.
Although the symptoms of a TIA usually resolve in 24 hours, they should not be ignored. A TIA is a warning sign of the possibility of a stroke.
Stroke
A stroke, although similar to a TIA, is much more severe and can result in permanent damage if not treated immediately. A stroke, also called a "brain attack," occurs when the blood flow to the brain is interrupted. Without proper blood flow, the cells of the brain begin to die, resulting in impairment of abilities such as movement, speech and vision.
A blocked carotid artery can cause a stroke in three different ways. The buildup of plaque can become so thick that the carotid artery itself becomes blocked. A small blood clot that normally would not cause a problem can block the carotid artery that is already partially blocked by plaque. Lastly, a piece of plaque can break away from the carotid artery, be carried to the brain and get lodged in a smaller artery where it restricts blood flow, resulting in a stroke.
