Touch your finger to your neck along your trachea: That pulsing you feel comes from your common carotids, two large arteries that pump oxygen-rich blood to the face and brain.

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Each side of the body has a carotid artery; the right common carotid originates in the neck from the brachiocephalic trunk, while the left arises directly from the heart’s aortic arch. From there, the two sides follow nearly identical paths.

Both arteries split into two branches at the base of the skull. The internal branch carries blood to the brain, while the external branch spreads out around the face.

If a carotid artery becomes blocked by fat and cholesterol buildup (called atherosclerosis or plaque), brain function and vision can be affected and a stroke can occur. Plaque in a carotid artery may cut off the flow of blood, or it may cause blood to flow abnormally and form a clot. Blockage can be detected by an ultrasound, CT scan, or angiography, in which dye is injected into the artery and x-rays are taken.

Patients whose carotid arteries are between 75 and 99 percent blocked usually have surgery to clear them out and restore blood flow to the brain. (A complete blockage, however, is too dangerous to be operated on.) A doctor may insert a plastic tube called a shunt into the artery above and below the blockage to reroute bloodflow while the plaque is removed. Narrowed or blocked arteries can also be treated with changes in lifestyle—implementing a low-fat, low-cholesterol diet and getting regular physical activity—and medications such as blood thinners and cholesterol-lowering drugs.

ADDITIONAL FACTS

  1. Doctors may listen with a stethoscope against the throat for something called a carotid bruit—an abnormal sound that indicates the presense of a fatty buildup and a higher stroke risk.
  2. A clot that stays in one place and blocks the flow of blood in an artery is called a thrombus. A clot that travels and wedges itself into a smaller vessel is called an embolism.
  3. A significant cause of stroke among middle-aged adults is carotid artery dissection, in which a small tear forms in the arterial lining and blood seeps into the space between vessel layers. Dissection usually results from blunt trauma to the head or neck, although spontaneous tears occur as well.