The brain needs a constant supply of blood to function properly, and it’s the job of the carotid artery to make sure this happens. The arteries run up either side of the neck and divide into two branches just below the angle of the jaw. One branch supplies blood to the face (external carotid artery), the other to the brain (internal carotid artery).
Hardening and narrowing of the arteries (atheroma or atherosclerosis) is a disease of all arteries in the body. When this occurs in the carotid arteries it causes strokes. Atheroma is caused by a combination of factors:
Lack of Exercise
What Causes a Stroke?
There are two main types of stroke. The most common is the ischemic stroke, when the blood supply to the brain is blocked by a clot. The other is a haemorrhagic stroke, which occurs when a blood vessel in the brain bursts. Atheroma causes narrowing and irregularity of the inside wall of the artery, particularly where it branches. This narrowing may restrict the blood supply to the brain. This usually causes no symptoms, and the brain adapts to the reduced blood supply. The irregular uneven walls to the artery can allow blood clots and debris to collect. These can break away and interrupt the blood supply to areas of the brain and cause a stroke. Complete blockage of the carotid artery can occur without any symptoms if the brains blood supply can be supplemented by other vessels. However, if this is not the case, parts of the brain can be deprived of a blood supply which may lead to a permanent stroke.
Symptoms of a Stroke
Both types of stroke cause loss of oxygen and vital nutrients to brain cells, which leads to damage or death of the cells. In the case of a TIA (Transient Ischemic Attack) or mini-stroke, the blood supply is only disrupted for a short while, and the patient recovers within 24-hours. It affects the face, arm, or leg on one side of the body. Sometimes there is loss of vision in one eye. Jumbled or complete loss of speech can also occur. A stroke has the potential to be fatal. Those who survive are left with permanent or temporary paralysis on one side of the body and may lose the ability to speak. Strokes affect those of increasing age, usually those of more than 60 years. They are more common in smokers, people with a high blood pressure, diabetics, and people with high cholesterol levels.