A carotid body tumor, also known as a chemodectoma or paraganglioma, is a tumor located on the side of the neck, where the large carotid artery branches into smaller blood vessels to carry blood into the brain. The cluster of cells around that branching is called the carotid body, or carotid glomus. The tumors that develop there are not life-threatening, but they can grow quickly and press on nearby nerves and blood vessels, causing damage to those structures. In some cases, a patient will develop multiple small tumors rather than a single tumor.
Carotid body tumors are relatively rare, occur in both men and women, and are most often seen in those who are middle aged or older. Carotid body tumors also tend to occur in people living at very high altitudes, possibly from the chronic lack of oxygen.