With giant cell arteritis, the lining of arteries becomes inflamed. This causes them to swell. This swelling narrows your blood vessels, reducing the amount of blood — and, therefore, oxygen and vital nutrients — that reaches your body's tissues.

Almost any large or medium-sized artery can be affected, but swelling most often occurs in the arteries located in the temples. These are located just in front of your ears and continue up into your scalp. Sometimes the swelling affects just part of an artery with sections of normal vessel in between.

Just what causes these arteries to become inflamed isn't known. Certain genes and gene variations may increase your susceptibility to the condition.

Oct. 02, 2015