The right common carotid originates in the neck from the brachiocephalic trunk; the left from the aortic arch in the thorax.

These split into the external and internal carotid arteries at the upper border of the thyroid cartilage, at around the level of the fourth cervical vertebra.

There are studies in the bioengineering literature that have looked into characterizing the geometric structure of the common carotid artery from both qualitative and mathematical (quantitative) standpoints.

It originates directly from the aortic arch, and travels upward through the superior mediastinum to the level of the left sternoclavicular joint.

[citation needed] Each vessel passes obliquely upward, from behind the sternoclavicular joint to the level of the upper border of the thyroid cartilage, where it divides.

The external carotid artery travels more closely to the surface, and sends off numerous branches that supply the neck and face.

When the sternocleidomastoid muscle is drawn backward, the artery is seen to be contained in a triangular space known as the carotid triangle.

The right common carotid may rise above the level of the upper border of the sternoclavicular joint; this variation occurs in about 12 percent of cases.

In other cases, the artery on the right side may arise as a separate branch from the arch of the aorta, or in conjunction with the left carotid.

The condition and health of the common carotid arteries is usually evaluated using Doppler ultrasound, CT angiography or phase contrast magnetic resonance imaging (PC-MRI).

The intima-media thickness of the carotid artery wall is a marker of subclinical atherosclerosis and it increases with age and with long-term exposure to particulate air pollution.